All Diseases

Paget's (PAJ-its) disease of the breast is a rare form of breast cancer. Paget's disease of the breast starts on the nipple and extends to the dark circle of skin (areola) around the nipple. Paget's disease of the breast isn't related to Paget's disease of the bone, a metabolic bone disease.

Paget's disease of the breast occurs most often in women older than age 50. Most women with Paget's disease of the breast have underlying ductal breast cancer, either in situ — meaning in its original place — or, less commonly, invasive breast cancer. Only in rare cases is Paget's disease of the breast confined to the nipple itself.

Painful intercourse can occur for a variety of reasons — ranging from structural problems to psychological concerns. Many women experience painful intercourse at some point in their lives.

The medical term for painful intercourse is dyspareunia (dis-puh-ROO-nee-uh) — which is defined as persistent or recurrent genital pain that occurs just before, during or after intercourse. Talk to your doctor if you're experiencing painful intercourse. Treatments focus on the underlying cause, and can help eliminate or reduce this common problem.

Pancreatic cancer begins in the tissues of your pancreas — an organ in your abdomen that lies horizontally behind the lower part of your stomach. Your pancreas secretes enzymes that aid digestion and hormones that help regulate the metabolism of sugars.

Pancreatic cancer often has a poor prognosis, even when diagnosed early. Pancreatic cancer typically spreads rapidly and is seldom detected in its early stages, which is a major reason why it's a leading cause of cancer death. Signs and symptoms may not appear until pancreatic cancer is quite advanced and complete surgical removal isn't possible.

Pancreatic cysts are sac-like pockets of fluid on or within your pancreas. The pancreas is a large organ located behind the stomach. It produces hormones and enzymes that help digest food.

Most pancreatic cysts aren't cancerous, and many don't cause symptoms. In fact, many pancreatic cysts technically aren't cysts at all. Called pseudocysts, these noncancerous (benign) pockets of fluids are lined with scar or inflammatory tissue, not the type of cells found in true cysts.

But some pancreatic cysts can be cancerous. Your doctor may want to take a sample of the pancreatic cyst fluid to determine if cancer cells are present.

Sometimes, your doctor may not be able to tell whether a cyst may become cancerous. Your doctor may recommend monitoring the cyst over time for changes in size or shape that may suggest the need to remove it surgically. Some cysts have a low potential for becoming cancerous, and your doctor may recommend watching them carefully.

Pancreatitis is inflammation in the pancreas. The pancreas is a long, flat gland that sits tucked behind the stomach in the upper abdomen. The pancreas produces enzymes that assist digestion and hormones that help regulate the way your body processes sugar (glucose).

Pancreatitis can occur as acute pancreatitis — meaning it appears suddenly and lasts for days. Or pancreatitis can occur as chronic pancreatitis, which describes pancreatitis that occurs over many years.

Mild cases of pancreatitis may go away without treatment, but severe cases can cause life-threatening complications.

A panic attack is a sudden episode of intense fear that triggers severe physical reactions when there is no real danger or apparent cause. Panic attacks can be very frightening. When panic attacks occur, you might think you're losing control, having a heart attack or even dying.

Many people have just one or two panic attacks in their lifetimes, and the problem goes away, perhaps when a stressful situation ends. But if you've had recurrent, unexpected panic attacks and spent long periods in constant fear of another attack, you may have a condition called panic disorder.

Panic attacks were once dismissed as nerves or stress, but they're now recognized as a real medical condition. Although panic attacks can significantly affect your quality of life, treatment can be very effective.

Paraneoplastic syndromes of the nervous system are a group of rare disorders that develop in some people who have cancer. Paraneoplastic syndromes of the nervous system are the most commonly reported paraneoplastic syndromes, but these syndromes can also affect other organ systems including hormone (endocrine), skin (dermatologic), blood (hematologic) and joints (rheumatologic).

Paraneoplastic events may also in part explain some of the most common symptoms of cancer, such as fatigue, loss of appetite for food (anorexia) and weight loss.

Paraneoplastic syndromes of the nervous system occur when cancer-fighting agents of the immune system also attack parts of the brain, spinal cord, peripheral nerves or muscle. Cancers commonly associated with these disorders include lung, breast and ovarian, as well as cancers of the blood. In most cases, paraneoplastic syndromes of the nervous system occur before a cancer is diagnosed.

Depending on the component of the nervous system affected, paraneoplastic syndromes can cause problems with muscle movement or coordination, sensory perception, memory or thinking skills, or even sleep.

Sometimes the injury to the nervous system is reversible with therapy directed toward the cancer and the immune system. However, these diseases can also rapidly result in severe damage to the nervous system which can't be reversed. Regardless, treatment of the underlying cancer and other interventions may prevent further damage, improve symptoms and give you a better quality of life.

Parkinson's disease is a progressive disorder of the nervous system that affects your movement. It develops gradually, sometimes starting with a barely noticeable tremor in just one hand. But while a tremor may be the most well-known sign of Parkinson's disease, the disorder also commonly causes stiffness or slowing of movement.

In the early stages of Parkinson's disease, your face may show little or no expression or your arms may not swing when you walk. Your speech may become soft or slurred. Parkinson's disease symptoms worsen as your condition progresses over time.

Although Parkinson's disease can't be cured, medications may markedly improve your symptoms. In occasional cases, your doctor may suggest surgery to regulate certain regions of your brain and improve your symptoms.

Parvovirus infection is a common and highly contagious childhood ailment — sometimes called slapped-cheek disease because of the distinctive face rash that develops. Parvovirus infection also has been known as fifth disease because, historically, it was one of five common childhood illnesses characterized by a rash.

In most children, parvovirus infection is mild and requires little treatment. However, in some adults, the infection can be serious. Parvovirus infection in some pregnant women can lead to serious health problems for the fetus. Parvovirus infection is also more serious for people with some kinds of anemia or who have a compromised immune system.

Patellar tendinitis is an injury to the tendon connecting your kneecap (patella) to your shinbone. The patellar tendon works with the muscles at the front of your thigh to extend your knee so you can kick, run and jump.

Patellar tendinitis, also known as jumper's knee, is most common in athletes whose sports involve frequent jumping — such as basketball and volleyball. However, even people who don't participate in jumping sports can get patellar tendinitis.

For most people, treatment of patellar tendinitis begins with physical therapy to stretch and strengthen the muscles around the knee.