Post-concussion syndrome (PCS) is when you have concussion symptoms that last months or even a year or more after your initial injury. The symptoms can affect you in many ways, including how your body and brain function, as well as how you experience emotions. Usually, concussion symptoms go away within two to six weeks after you experience an injury. People receive a …

Your peritoneum is a thin membrane that lines the inside of your belly (abdomen) and wraps around the organs inside. Peritonitis is the term for inflammation of the peritoneum. The tissues can become inflamed if they’re exposed to irritating or infected body fluids. This usually happens when something inside leaks or breaks. Infection is the most common cause of peritonitis, and it can be …

Peripheral nerve tumors are growths that form in or near nerves. Nerves are strands of tissue that transmit signals from the brain to the rest of the body. Peripheral nerves control muscles that allow you to walk, blink, swallow, pick things up and do other activities. Peripheral nerve tumors can occur anywhere in the body. Most of them are benign, …

Peripheral nerves send messages from the brain and spinal cord to the rest of the body. They help do things such as move the body’s muscles for walking and sense that the feet are cold. Peripheral nerves are made of fibers called axons that are insulated by surrounding tissues. Peripheral nerves are fragile and easily damaged. A nerve injury can …

Perimenopause is when your body starts transitioning to menopause. During this transition, your ovaries begin producing less hormones, causing your menstrual cycle to become erratic or irregular. In perimenopause, your body is moving toward the end of your reproductive years. It’s a natural and normal progression, but it comes with both physical and emotional symptoms. Some of these symptoms can disrupt your life or …

Pemphigus is a group of autoimmune skin conditions that cause sores, blisters or fluid-filled bumps to form on your skin. These blisters can also form in your mucous membranes, which are the soft linings of your eyes, nose, mouth, throat and genitals. The blisters are soft and break open easily to form painful sores. Without treatment, they can spread over large areas …

Pelvic organ prolapse (POP) is when your pelvic organs (vagina, uterus, bladder, rectum) drop from their typical positions. It happens when your pelvic floor (the muscles, ligaments and tissues that support your pelvic organs) become too weak to hold your organs in place. Your pelvic floor supports the organs in your pelvis from underneath — almost like a hammock. If these supports …

Pelvic inflammatory disease (PID) is a serious infection in your uterus, fallopian tubes and/or ovaries. It affects women and people assigned female at birth (AFAB). PID develops when certain types of bacteria spread from your vagina to your reproductive organs. Bacteria from untreated sexually transmitted infections (STIs) are the most common cause of PID. However, bacteria normally found in your vagina can also cause PID. When you …

Polycystic ovary syndrome (PCOS) is a hormonal imbalance that occurs when your ovaries (the organ that produces and releases eggs) create excess hormones. If you have PCOS, your ovaries produce unusually high levels of hormones called androgens. This causes your reproductive hormones to become imbalanced. As a result, people with PCOS often have irregular menstrual cycles, missed periods and unpredictable ovulation. Small follicle cysts …

Patent ductus arteriosus (PDA) is a heart condition in babies. It happens when a blood vessel called the ductus arteriosus doesn’t close as it should after birth. What does the ductus arteriosus do? During fetal development (before a baby is born), very little blood flows to a baby’s lungs. Instead, most of the blood bypasses the baby’s lungs. One way for this to …