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Your pituitary gland is a pea-sized gland at the base of your brain. The pituitary is the "master control gland" - it makes hormones that affect growth and the ...
Plague is an infection caused by the bacterium Yersinia pestis. The bacteria are found mainly in rats and in the fleas that feed on them. People and other animals ...
Surgeons can reshape the appearance of body parts through cosmetic surgery. Some of the most common body parts people want to improve through surgery include: ...
Platelets, also known as thrombocytes, are blood cells. They form in your bone marrow, a sponge-like tissue in your bones. Platelets play a major role in blood ...
Your pleura is a large, thin sheet of tissue that wraps around the outside of your lungs and lines the inside of your chest cavity. Between the layers of ...
Pneumococci are a type of streptococcus bacteria. The bacteria spread through contact with people who are ill or by healthy people who carry the bacteria in the ...
What is Pneumocystis jirovecii? Pneumocystis jirovecii is a fungus that is common throughout the world. Many people have been exposed to it as children. ...
What is pneumonia? Pneumonia is an infection in one or both of the lungs. It causes the air sacs of the lungs to fill up with fluid or pus. It can range ...
If you spend time outdoors, chances are you have been bothered by poison ivy, poison oak or poison sumac at some point. Most people are sensitive to the ...
A poison is any substance that is harmful to your body. You might swallow it, inhale it, inject it, or absorb it through your skin. Any substance can be ...
What is polio? Polio, or poliomyelitis, is a disease that spreads from person to person. It is caused by the poliovirus. The virus attacks the nervous ...
What is polycystic ovary syndrome (PCOS)? Polycystic ovary syndrome (PCOS) is the name for set of symptoms that are related to an imbalance of hormones. ...
Polymyalgia rheumatica is a disorder that causes muscle pain and stiffness in your neck, shoulders, and hips. It is most common in women and almost always occurs ...
Porphyrias are a group of genetic disorders caused by problems with how your body makes a substance called heme. Heme is found throughout the body, especially in ...
What are post-COVID conditions (long COVID)? COVID-19 (coronavirus disease 2019) is an illness caused by a virus. Many people get better within a few days ...
What is post-traumatic stress disorder (PTSD)? Post-traumatic stress disorder (PTSD) is a mental health disorder that some people develop after they experience ...
Taking home a new baby is one of the happiest times in a woman's life. But it also presents both physical and emotional challenges. : Get as much rest as possible. ...
Many women have the baby blues after childbirth. If you have the baby blues, you may have mood swings, feel sad, anxious or overwhelmed, have crying spells, ...
Potassium is a mineral that your body needs to work properly. It is a type of electrolyte. It helps your nerves to function and muscles to contract. It helps your ...
Prader-Willi Syndrome (PWS) is a rare genetic disorder. It causes poor muscle tone, low levels of sex hormones and a constant feeling of hunger. The part of ...