3 Highly Effective Study Habits

3 Highly Effective Study Habits

Students confront many issues in their lives, and because of all of the challenges you deal everyday, it’s very difficult to concentrate on studying. And yet if you are in school, you have to do at least a little studying in order to grow from year to year.

The gold to effective studying it’s not in studying longer, but studying wiser. You can start studying wiser and smarter with these 3 proven and truly effective studying habits.

1: It matters how you approach your studying

So many people look at studying as a mandatory task, not an pleasure or opportunity to learn. That’s ok, but experts have found that how you approach something matters as much as what you do.

Sometimes you can not “force” yourself to be in the right spot, and it is during such times you should simply dodge studying. If you are (maybe) distracted by a relationship issue or finishing an essential project, then studying is just going to be a frustration for you. Come back when you are not obsessed by something else going on in your life.

2: The place you study is important

A lot of people make the mistake of studying in a place that don’t give you the right focus. Place with a lot of distractions makes it a poor study area. For an example,If you try and study in your dorm room, you may find your TV, computer or your roommate more interesting than the reading material you are trying to master.

The library is quiet area and good place where you can settle down and study. Search for multiple places on or of your campus – do not pick the first spot that you find “good enough” for your needs. Finding an perfect study place is very important, because it’s one you can count on for the next few years of your studying.

3: Start using memory games / mnemonic devices

Memory games known as mnemonic devices, are good methods for remembering pieces of information using a transparent association of some common words. Often people twist together words to form a nonsense sentence that is easy to remember.

The first letter of each word can then be used to stand for something else – the piece of information you’re trying to remember. This method don’t work for everyone, so if they start making you trouble, don’t use them.

Mnemonic devices are truly helpful, because you will start using your brain more to remember visual and active images than you do to remember only a list of items.

Image credit: Photographer:Wavebreakmedia

Sorrow Of The Dentist by Ayam Chhatkuli

And now, something slightly different than what you would expect from Meddy Bear. We are here to prove that doctors also have an artistic side to them.

We present to you a poem written by one of our fans, Ayam Chhatkuli from Nepal.






Sorrow of the dentist

Before I joined the med school

the focus of my sight was different

I used to see a whole human

All I see now is the teeth with calculus and stain.


When I see an old man walking

all I remember is a complete denture

I’m fed up with my prostho work

help me God I surrender


The man has a class I fracture

46 got a root stump

A life with no joy and rupture

Is equal to a dump


I come to encounter mainly 2 sorts of patients

Few are philosophical

And many are hysterical


People actually are very unhygienic

They bath with Quatar soap and have a Jean Patou’s spray

But use a single brush for 6 months

and walk with a grossly decayed tooth till the next may


Inside the heat of this mask

My beard failed to grow

Nose felt difficult to breath

Salivation decreased its flow


These days I dream of teeth

Good dreams angels appear as a canine

Bad dreams impacted lateral at age nine

She insists to describe her beauty

All I can see is her anterior cross-bite

with peg laterals

Falling in love for a dentist

is almost like winning the battles.

Breakthrough technology joins forces with Medicine- the future of Human Anatomy

How can new technologies help educate the medical professionals?

We live in a time when everything changes not even by year, not by month and not really a day – it comes down to a smaller measure of time when talking about the progress of new technology. As Moore’s law has predicted for decades, the number of transistors in a dense integrated circuit doubles every two years as the electronical aids improve. This, of course, directly translates to the capabilities of such devices. So, where have we gone now, in 2017?

Digital anatomy and pathology books are a thing that we are already used to by now. The newest technology does not even reside in various 3D models that became available a few years ago. When exploring the newest capabilities, we came across an amazing rising star among the many digital anatomy learning tools – Anatomy Next. Based in Seattle, they have developed an amazing collection of high-resolution 3D models of cranial nerves, incredibly simple-to-learn yet detailed schemes along with renders that might want to make you question your ability to distinguish them from the real thing. The biggest improvement, though, is the introduction of augmented reality in the world of medical education tools. This is achieved by exploiting the impressive capabilities of Microsoft Hololens – a tool that makes the augmented reality really come into life.



It is long known that visualizing things makes us remember them better, and this advancement does exactly that – it helps anything that can be rendered come in your life; literally. The holographic glasses allow the user to select any of the given anatomy models and project them in front of their eyes. The model then can be adjusted by hand signals, allowing the user to move, rotate, lean it any way the user wishes, and Anatomy Next model is an even more detailed one. Let’s give an example here – you have a highly-detailed render of the skull in front of you. The application allows you to delete or fade out parts of it, take a look at them from any angle you wish, see the most detailed parts in close-up and use the application’s ability to label the bones and parts of them. Now this is learning, not some old, dusty books!

Have you tried this or would like to do so? Give us a shout-out below and share your thoughts!

Think with your skull!

For most people, skulls symbolise pirate chests or some ancient times. Some people only associate skull with death without which we wouldn’t be able to examine beauty and complexity of it. But for us, medical professionals, it associates with medicine, with something exquisite and detailed; as I personally was learning about the bones of the skull in my first year anatomy class, I became completely fascinated of how precise and well – made it is.

Well, what exactly is it made of? It is comprised of 22 bones which are tightly joined together by fibrous joints called sutures. These sutures allow the cranium to act as a whole and serve its primary purpose of protecting the inner organs, namely the brain. For the means of simplicity and logic the anatomy of it can be divided in the roof or the calvarium, and the base. The calvarium is made of the frontal, occipital bones and two parietal bones, and the base of the cranium which support the brain and provide articulation points for the atlas vertebra and mandible is made of the sphenoid, frontal, ethmoid, occipital, parietal and temporal bones.

This is overview of the cranial anatomy. But what about our face? What makes our facial expressions so characteristic and gives us our individual look? 14 bones are the supporters of the facial muscles and organs and the only movable cranial bone is one of the facial ones – the mandible. The other 13 are two maxillae, vomer, two palatine, two nasal, two zygomatic, two nasal conhae and two lacrimal.

Except for the mandibular bone, the bones in the cranium are joined together by a joint that cannot be found anywhere else in the human body – sutures. In the newborn they haven’t all fused together quite yet and form the frontal and occipital fontanelles, but by the approximate time one has reached 20 years of age, they are fused together and are immovable. The most notable sutures in the adult cranium are coronal, sagittal and lambdoid. It is the crossing of those sutures that form aforementioned fontanelles in a newborn.

Knowing the anatomy of cranium is amazing; the complexity of it is just amazing. But in medical school it is usually one of the toughest bone complexes to learn. How can you help yourself improve the experience? The best tool we have found just might be Anatomy Next – not only they have an amazingly detailed renders of 3D anatomy, these models are also available in augmented reality, including Microsoft Hololens. Have you tried it? Share your thoughts below!

Dr Ruth Pfau, life of a humble leprosy doctor

 Dr Ruth Katherina Martha Pfau (9 September 1929 – 10 August 2017), German doctor and nun, has passed away during a surgery procedure in Karachi. She was 87 years old. Dr Pfau, also known as Pakistani Mother Teresa, devoted her whole life to treating leprosy patients in Pakistan.

Dr Pfau was born in Leipzig, Germany. After World War II, she escaped to West Germany with her family, and decided to study medicine. In the 1950s she studied medicine at the universities of Mainz and Marburg.

After finishing her studies and joining Catholic order (Daughters of the Heart of Mary), she was on her way to India. But, after facing visa problems, she was redirected to Pakistan.

Dr Pfau witnessed leprosy for the first time in 1960, upon arriving to Pakistan. The illness she never heard of, or knew exsisted. The images of disfigured and socially excluded people she saw upon arrival, motivated her to do all she can to eradicate leprosy.


She was the founder of the Pakistan’s National Leprosy Control Programme and the Marie Adelaide Leprosy Centre. She helped numerous people who suffered from the illness, reaching the figure of 50,000 treated patients.


Dr Pfau went on and opened branches in all Pakistan provinces. She provided training to Pakistani doctors and volunteers and worked on attracting foreign donations. As a result, in 1988, she was granted Pakistani citizenship.


Finally, after 38 years of her efforts, in 1996, Pakistan was one of the first countries in Asia to be declared leprosy free by World Health Organization.

She has also helped in rescuing victims from the 2005 earthquake and floods that caught south western part of Pakistan in 2010.   She received numerous honours for her work, among them the Hilal-e-Imtiaz – Pakistan’s second highest civilian award – in 1979, the Hilal-e-Pakistan in 1989 and the German Staufer Medal in 2015. On 14 August 2010, the President of Pakistan awarded Dr Pfau the Nishan-i-Quaid-i-Azam for public service. Yet, despite all her achievements, she stayed humble and was never indiferent to pain and suffering of others.

She was the author of  four books: The Last Word is Love: Adventure, Medicine, War and God, To Light A Candle. In the books she wrote about her work in Pakistan.

The funeral for the late Dr Ruth Pfau will be held on 19 August at St Patrick’s Cathedral in Karachi.



Experts agree that high cholesterol and blood pressure are decisive heart disease risk factors, but many people who suffer from chest pain or even from heart attacks have levels that are faultlessly normal. This problem has inspired experts to scour the body for other cardiovascular villains. A few have emerged in recent years, but the one that stands out the most is inflammation.

Image credit: Photographer: stuartmiles

The latest studies suggest that chronic inflammation of the lining of arteries is an important factor in the expansion of atherosclerosis and coronary heart disease. What is the source of this inflammation is not clear, but the good news is that:

  • 1: the instruction that is given for lowering blood pressure, cholesterol and triglycerides also works fine for fighting inflammation; and
  • 2: you can tackle all 4 culprits with the help of dietary weapons. In fact, you can plan your battle against heart disease home, in your kitchen. Here is how:
  1. Start thinking like a professional when you choose the right fruits and vegetables: You should start eating those with the brightest colors.

Those have the most heart protective antioxidant pigments. A proper diet high in fruits and vegetables, also provides another significant heart benefit – salicylic acid, which is the same anti-inflammatory compound created when aspirin is added down in the body.

2. Start increasing food sources of the omega-3 fatty acids which targets high triglycerides in your blood system.

Proper sources of omega-3s, include fish such as sardines or mackerel; light green leafy vegetables; nuts and seeds; grains like wheat; cowpea and also black gram.

3. Reduce the amount of meats you eat, especially the red meats, and always select lean cuts.

  1. Decrease using of salt – instead use herbs and spices like garlic, ginger, turmeric and fenugreek liberally in your cooking;
  2. Change to groundnut, mustard, rice bran and olive oils which have monosaturated fatty acids that help lower (bad) LDL and control levels of (good) HDL cholesterol. Drastically lower down the use of margarine, butter, vegetable shortening and all products that are made with partially hydrogenated oils.
  3.  Fruits and vegetables, beans and pulses, are also tremendous sources of soluble and insoluble fibre, which trap LDLs and usher them out of your body.

How To Sleep Good

Posted on Quora by Nela Canovic
Try these 9 hacks to prepare for getting a good night’s sleep.

  • Set a bedtime alarm on your phone to go off 30 minutes before you need to sleep, which will signal to you that you need to finish up whichever activities you’re working on. Be sure to have a bedtime alarm go off every day of the week, including weekends.
  • Reconsider your dinners and when you eat at night. In addition to having a busy mind, you may feel sluggish and also experience difficulty falling asleep at night due to heavier foods or eating late. Avoid fried food and caffeine (which can be in some desserts and sugary drinks), and instead go with a lighter dinner with a big salad. Schedule your dinner at least a few hours before your bedtime.
  • Take a short walk after dinner. It can be just 20-30 minutes. Being outside is good for your digestion, you get some fresh air, and you rest your mind from all the activities you’ve completed during your busy day. A walk also sends signals to the body that it’s time to unwind and relax.
  • Get away from electronics (computer and TV) in the hour before bedtime. Instead, listen to a podcast on a topic you find interesting, queue up some relaxing music and listen with your eyes closed as you’re sitting on the couch, or read a book to stimulate your imagination.
  • Start a productivity planner before going to bed. Write a list of items that are top priority for the next day, mark them in the order of importance, note down how long you think you’ll work on each activity. This technique is useful because you train your mind to focus a few steps ahead so you don’t worry about forgetting something important, which in turn might keep you awake at night.
  • Have a cup of herbal tea (no caffeine), some warm milk with honey, or a magnesium supplement (either tablet or powder form) around the time your alarm goes off. These warm drinks can help you feel more sleepy.
  • Make your room sleep-friendly. Sleep in a well ventilated room, keep your window open at least a little, raise the blinds or move the curtains aside to let daylight in, and don’t place anything on your eyes so that your body can react to the natural morning light when it’s time to wake up. To prevent any noise from waking you up, invest in a good pair of soft silicone ear plugs like these so you can sleep through the night.
  • Take a deep breath of lavender. Lavender oil is often used to calm the senses and can help us relax before going to sleep. Keep a bottle on your night stand, and before you close your eyes, put 3–5 drops into the palm of your hand, then rub your palms together to release the essence of the oil. Inhale deeply a few times, then run your fingers over your temples, forehead, around your nose, and smooth them over your pillow for an additional soothing effect.
  • Optimize your sleeping pattern. There are always resources at your fingertips for turning sleep into a positive and lasting habit. Try one of these to get more ideas:

Gonorrhea slowly becomes incurable

Gonorrhea slowly becomes incurable

Gonorrhea (trigger or cap) – contagious sexually transmitted disease, which is spread by sex contact, can be transmitted from the mother to the fetus during pregnancy, and very rarely through contaminated objects (clothing, crop, shunter) and its causing the so called bacteria Neisseria gonorrhea. A source of infection is an infected person and is transmitted by direct sexual contact through the skin and mucous membrane of the genital organs. The clinical picture of gonorrhea is different in men and women.

The World Health Organization (WHO) announced a dramatic announcement urging people to use condoms during sexual intercourse, due to an elevated degree of gonorrhea, which, unfortunately, in some cases has become antibiotic-resistant.

“The bacteria is extremely intelligent. Whenever we apply a new series of antibiotics to treat the infection, it develops and becomes resistant. The fact is that poor countries do not have a monitoring system and its diagnosis, “explains Theodora Vi, an expert at the “WHO”.

Based on data collected from as many as 77 countries in the world, the World Health Organization has issued a statement warning the alarming results that this bacteria is more resistant. Apart from the fact that the old antibiotics no longer work on the bacteria, it’s worrisome that even the new generation of antibiotics are not effective in some cases.

According to the “WHO”, the gonorrhea infects as many as 78 million people annually, and the number of infected people is steadily increasing.

Symptoms may be mild or unbearably painful and cause abdominal pain and fever with high temperature. If a pregnant woman has gonorrhea, she can infect the baby during her birth, or while it passes through the birth canal. Infection can cause blindness, an infection of the joints, or an infection of the blood that can be life-threatening.

Image credit: Photographer:Sergejs Rahunoks

Antibiotics for a virus?


Imagine the following scene. You are lying in bed, your throat hurts, nose is running, your whole body is in pain, you feel weak. In comes your mother (sister, father…etc. ) and tells you to go and see a doctor, they will give you antibiotics and you will feel much better.

Sounds familiar? Everyone has experienced this at least a few times in a lifetime.

Why is using antibiotics for treatment of viruses wrong?

Well, first and foremost, antibiotics do not have any effect on viral infections. In a nutshell, antibiotics don’t kill viruses, because viruses have different structure than bacteria, and also, they replicate in a different manner. Antibiotics are specifically designed to kill bacteria, or prevent their further regrowth.

Taking antibiotics for viral infection will not cure the infection, nor it will help you feel better, and certainly will not prevent other people from getting sick. Also, inappropriate use of antibiotics can cause harmful side effects. Simply, it can cause more harm than good.

How do antibiotics work? They interfere with the bacterial cell wall and therefore prevent bacterial replication. Due to widespread use of these drugs, bacteria have found a way to adapt, by strengthening their own cell walls and by producing enzymes that can inactivate the antibiotic.

Number two, overuse of antibiotics can lead to antibiotic resistance. Research has shown that up to one-third to one-half of antibiotic use is either unnecessary or inappropriate. Resistant bacteria are stronger and therefore harder to treat.

Antibiotic resistance can also lead up to rise in superbug infections.  Parts of the world where there has been an alarming spread of superbugs include Israel, Greece, India, China and as been reported, also on the rise in Australia.


So, what’s our advice?

  • Never take any medication on your own, before consulting with your doctor.
  • Respect doctor’s advice. Do not insist on getting prescription antibiotics if you suffer from cold, flu, sore throat and other viral infections.
  • If you have any type of viral infection, you should: drink more fluids, get plenty of rest, consult your physician about over-the-counter treatment options that may help reduce symptoms.


The reason we don’t get a heart cancer

Your heart

Your heart is virtually impervious to cancer due to its muscular, non-fatty nature along with substantial assistance from the pericardium.
Food for thought: there are cancers of the brain, blood, lymph nodes, lungs, bone, and every other bodily organ, part, or system imaginable. Why, then, do we never hear about heart cancer
Could it be our hearts, long symbolized as the root of loving emotion, are somehow immune to the dreaded disease?
Unfortunately, the reason no one ever talks about heart cancer is much more mundane.
“We do have tumors that occur in the heart,” Dr. Jacqueline Barrientos, assistant professor, Hofstra North Shore-LIJ School of Medicine said “but these are not as common, so you don’t hear about them.”
Indeed, malignant heart tumors, known as rhabdomyosarcomas, are extremely rare. A sarcoma is a type of tumor that originates in the soft tissues of the body; a rhabdomyosarcoma occurs in the muscle tissue of the heart. Their incidence is estimated at less than 0.1 percent, based on a study of more than 12,000 autopsies, which identified only seven cases of any kind of primary cardiac tumor. (Primary tumors are those that have originated where they are found, and have not spread from some other part of the body.)

That said, “most cancers found in the heart have come from elsewhere in the body,” according to Dr. Timothy J. Moynihan of the Mayo Institute, meaning they are secondary tumors. To understand exactly what he means, it might be necessary to review the fundamentals.

Our bodies have an astronomical number of cells — uncountable, really — though one estimate places the number at 37.2 trillion. When we are healthy, our many cells cooperate and share the vast work of our body, all while they go about their separate business of growing, dividing (to provide a replacement for themselves), and then efficiently dying. Cancer, then, is simply an aberration of these cellular processes.
Cancer begins when cells start to grow out of control. This is due to damaged DNA, the genetic material carried in the nucleus of each and every cell. Normally, a cell repairs any damaged DNA, or simply dies, but cancer cells do not repair or die. Instead, they divide and make many more abnormal cells with damaged DNA. Another unusual property possessed by cancer cells is they are able to grow into —invade, really — other tissues. Normal cells cannot do the same.
So, when Moynihan says cancers in the heart have come from “elsewhere in the body,” he is talking about just such an invasion — the cancer began somewhere else in the body, but now it has infiltrated the heart.

Dr. Mitchell Gaynor, clinical assistant professor at Weill Cornell Medical College, told Medical Daily the most common secondary tumors spreading to the heart “come from the lung, from the esophagus, and you can also see them from the liver, and the stomach. Even nests of leukemia cells form tumors in the heart.” More importantly, all of these different types of tumors “usually go to the right side of the heart,” Gaynor explained. “That’s where the blood enters the heart — on the right side.”

But a tumor is a tumor is a tumor, you say. How do doctors know where a tumor originates — especially when a new tumor may appear years later in a part ofthe body far from the original cancer site? When a new tumor appears, its cells are identical to those of the original tumor. So if a person had pancreatic cancer, say, and it spread to the brain, the tumor appearing in their brain, when viewed through a microscope, would look nothing like the tumor of a person with brain cancer — the cells of this brain tumor would look identical to pancreatic tumor cells.

If secondary tumors invade the heart, why is it so rare for primary tumors to develop there? According to Gaynor, the explanation begins and ends with our genes.

As you likely know, we receive half our genes from our mothers, half from our fathers. While it would seem our genetic fate is sealed, “nothing could be further from the truth,” said Gaynor, whose new book on the subject, The Gene Therapy Plan, “We understand now how gene expression can be modified throughout your life… and that can create cancer,” he said.
In fact, our environment affects which genes become expressed (activated) as well as how frequently they become activated. And carcinogens coming from our food and environment are one of the many factors that influence which genes are activated or not. “A lot of toxins are found in breast tissue, because there are a lot of fat cells there,” Gaynor explained. “And toxins are found wherever there is the most fat.” While our bodies have some defenses against these contaminants, in the form of detoxifying enzymes, and while our bodies are supported.

By Ammar Yasir Tariq Medical student From Iraq.



For those you know us and follow us, you may remember the image we shared on our facebook page that clearly describing what’s really going on in the operation room.

Originally, the image was taken in ER in Israel but the exact location we didn’t share because of privacy reasons.

(THE IMAGE CONTAINS GRAPHIC CONTENT – You can see the image here.)

The main goal and the purpose of the image was to raise awareness, not just to the medical stuff it self, but to all patients and family that are waiting in our hospitals halls or waiting rooms. There is a lot of violence against the medical team these days. In Israel a while ago one nurse was burned until death by a patient and we hear a lot of similar cases also in India and other countries.

The moment we shared the image, it went viral. Today, on facebook it has 20 million reach, 69 thousands of reactions and more than 150,000 shares combine on different facebook pages.

Huffington post made a article about this. The original article is in German language and you can find it on this link.

Like we sad, the aim of the picture is to raise awareness and show the reason behind the long waiting on ER, so people with smaller injuries understand why they wait because someone else is fighting for his life.

We truly hope that we can make some changes on the global opinion regarding the doctors. They are fighting for our lives every day. They are our heroes, but they are also human beings. Don’t forget that.


Why I chose medical career?

Well, I chose Medicine for various reasons.

  • First of all, I love studying our body; it’s wonderful to know how your body really works.

It’s amazing to discover, that there are a lot of cells that we can’t see with our own eyes, which have to work daily to keep us alive (Thanks guys!)

Our heart keeps beating day by day, many organs function without our influenceWhat can you say to that, rather than Wow?

  • A sentiment I didn’t find in any other profession other than medicine, is when you help a patientWhether  you save his/her life or do anything to improve it and the next thing you see is the smile on their face. This sensation is indescribable and it fills your heart with joy and accomplishment. It’s the best feeling in the world! To know you’ve done something to help others and to know they get to continue with their everyday life, all thanks to you.
  • Medicine is international. Being a doctor, you can work in the whole world, you can help anyone, around the globe, even without knowing local language…Medicine is universal, it speaks for itself.  One day, you may be sitting in your private practice in London, and next day someone can call you as an expert to visit Africa, or New Zealand, to help with a certain case. As a result, you may visit places you’ve only dreamed of.  Probably not the worst outcome 🙂

    Background vector created by Photoroyalty – Freepik.com

My big dream is to become a Pediatrician. I love kids so much, I think they are much better than adults (that’s my personal view for sure) as they are honest and straightforward. You cannot trick a kid, they will see right through you.

A kid’s smile is worth more than all the money of the world. When I am sad or not in the best mood, the only thing that can put a smile back on my face is a cute baby, with those chubby cheeks and giggling. After seeing this- everything is right in the world again 🙂

Medicine is not a normal course, it’s very hard and it consumes all your life. But, it also gives you a special view of life and certain path that u have to follow, if you decide to begin this journey.
If you want to be omniscient and study everything, your life will be hard. Our body’s anatomy is too much complicated for any person to memorize to the very detail… it will take you years.

With medicine, studying never really ends and you can count on many sleepless nights with book in your hands.
Ultimately, if this is your passion, I say, go for it! If you want to be the best at your job, first you have to love it. With medicine you can call it tough love 🙂

After finishing medical school, you will have to decide upon certain specialty you want to take. This is a breakthrough moment for many doctors.

Some may decide not to take a specialty at all, becoming general practitioners. Yet, others will become surgeons, gynecologists, oncologists knowing that they enrolled into medical school only to pursue that career.

Certain percent may even take into account the salary given, and as a result choose the specialty according to current market demand.

Therefore, be sure to choose what you love doing. You know the saying: ” Choose a job you love, and you will never have to work a day in your life.”

I believe this is true. And in the medical field, especially… When you love what you do, spending days at the hospital, taking care of patients, comes much easier. No one wants to be treated by a grumpy or unhappy doctor. And as a doctor, the stakes and expectations are high- you must always do your best!  But in the end, it’s also very rewarding.

So word of advice, when it comes to your specialty, choose wisely!

Cover picture by Wavebreakmediayayimages.com

Dr H.Nawatha
Founder at Meddy Bear

What is the Difference Between a Pandemic, Endemic and Epidemic Disease?

The question was posted on Quora and answered by Prakash Kamale

The amount of a particular disease that is usually present in a community is referred to as the baseline or endemic level of the disease. This level is not necessarily the desired level, which may in fact be zero, but rather is the observed level. In the absence of intervention and assuming that the level is not high enough to deplete the pool of susceptible persons, the disease may continue to occur at this level indefinitely.

Thus, the baseline level is often regarded as the expected level of the disease. While some diseases are so rare in a given population that a single case warrants an epidemiologic investigation (e.g., rabies, plague, polio), other diseases occur more commonly so that only deviations from the norm warrant investigation.

Sporadic refers to a disease that occurs infrequently and irregularly. Endemic refers to the constant presence and/or usual prevalence of a disease or infectious agent in a population within a geographic area. Hyperendemic refers to persistent, high levels of disease occurrence.

Occasionally, the amount of disease in a community rises above the expected level. Epidemic refers to an increase, often sudden, in the number of cases of a disease above what is normally expected in that population in that area. Outbreak carries the same definition of epidemic, but is often used for a more limited geographic area.

Cluster refers to an aggregation of cases grouped in place and time that are suspected to be greater than the number expected, even though the expected number may not be known. Pandemic refers to an epidemic that has spread over several countries or continents, usually affecting a large number of people.