Top videos

• All Time
• Today
• This week
• This month
• This year

Allergies, what causes them? This animated video reviews the pathophysiology of allergies, what causes them and why the symptoms occur. Food allergies, seasonal allergies and allergies to pollen all occur through a similar mechanism.

fetal position in womb at 34 weeks fetal position in womb week by week fetal position in womb at 19 weeksUnborn babies toss and turn and hold many different positions within the womb during the gestation period; pregnant women everywhere will attest to the fact that their children always start up the gymnastics at bedtime.

Panic attack from Injection:'(

Lichen sclerosus is a skin condition that mainly affects the genital skin (vulva) in women and the penis in men. It most commonly occurs in middle-aged women. Symptoms may include itch, soreness, and changes in the appearance of affected skin.

Ulcerative colitis (UL-sur-uh-tiv koe-LIE-tis) is an inflammatory bowel disease (IBD) that causes long-lasting inflammation and ulcers (sores) in your digestive tract. Ulcerative colitis affects the innermost lining of your large intestine (colon) and rectum. Symptoms usually develop over time, rather than suddenly. Ulcerative colitis can be debilitating and sometimes can lead to life-threatening complications. While it has no known cure, treatment can greatly reduce signs and symptoms of the disease and even bring about long-term remission.

A heart attack is a medical emergency. A heart attack usually occurs when a blood clot blocks blood flow to the heart. Without blood, tissue loses oxygen and dies. Symptoms include tightness or pain in the chest, neck, back, or arms, as well as fatigue, lightheadedness, abnormal heartbeat, and anxiety. Women are more likely to have atypical symptoms than men. Treatment ranges from lifestyle changes and cardiac rehabilitation to medications, stents, and bypass surgery.

Menopause is defined as occurring 12 months after your last menstrual period and marks the end of menstrual cycles. Menopause can happen in your 40s or 50s, but the average age is 51 in the United States. Menopause is a natural biological process. Although it also ends fertility, you can stay healthy, vital and sexual. Some women feel relieved because they no longer need to worry about pregnancy. Even so, the physical symptoms, such as hot flashes, and emotional symptoms of menopause may disrupt your sleep, lower your energy or — for some women — trigger anxiety or feelings of sadness and loss. Don't hesitate to seek treatment for symptoms that bother you. Many effective treatments are available, from lifestyle adjustments to hormone therapy.

Thoracic outlet syndrome affects the space between the collarbone and first rib (thoracic outlet). Common causes include trauma, repetitive injuries, pregnancy, and anatomical defects, such as having an extra rib. Symptoms include pain in the shoulders and neck and numbness, weakness, and coldness in the fingers. Treatment involves physical therapy and pain relief. In rare cases, surgery may be needed to relieve the compression.

Osteoporosis causes bones to become weak and brittle — so brittle that a fall or even mild stresses such as bending over or coughing can cause a fracture. Osteoporosis-related fractures most commonly occur in the hip, wrist or spine. Bone is living tissue that is constantly being broken down and replaced. Osteoporosis occurs when the creation of new bone doesn't keep up with the removal of old bone. Osteoporosis affects men and women of all races. But white and Asian women — especially older women who are past menopause — are at highest risk. Medications, healthy diet and weight-bearing exercise can help prevent bone loss or strengthen already weak bones.

Possible causes include a combination of biological, psychological, and social sources of distress. Increasingly, research suggests these factors may cause changes in brain function, including altered activity of certain neural circuits in the brain. The persistent feeling of sadness or loss of interest that characterizes major depression can lead to a range of behavioral and physical symptoms. These may include changes in sleep, appetite, energy level, concentration, daily behavior, or self-esteem. Depression can also be associated with thoughts of suicide. The mainstay of treatment is usually medication, talk therapy, or a combination of the two. Increasingly, research suggests these treatments may normalize brain changes associated with depression.

Demonstration of horizontal mattress suturing technique for laceration repair or wound closure in the operating room.

Bone marrow is the soft, sponge-like material found inside bones. It contains immature cells known as hematopoietic or blood-forming stem cells. (Hematopoietic stem cells are different from embryonic stem cells. Embryonic stem cells can develop into every type of cell in the body.) Hematopoietic stem cells divide to form more blood-forming stem cells, or they mature into one of three types of blood cells: white blood cells, which fight infection; red blood cells, which carry oxygen; and platelets, which help the blood to clot. Most hematopoietic stem cells are found in the bone marrow, but some cells, called peripheral blood stem cells (PBSCs), are found in the bloodstream. Blood in the umbilical cord also contains hematopoietic stem cells. Cells from any of these sources can be used in transplants.

This procedure describes proximal humeral fracture fixation with an angular stable plate (A). Sometimes, these implants are not available. Standard plates provide an alternative option, for example the modified cloverleaf plate (B). Presently, the specific indications, advantages, and disadvantages of angular stable and standard plates are being clarified. There is some evidence that angular stable plate provide better outcomes. In addition to type and technique of fixation, the quality of reduction, the soft-tissue handling, and the characteristics of the injury and patient significantly influence the results. There is no evidence that the use of angular stable plates will overcome these other factors.

Wetness. Even the most absorbent diaper leaves some moisture on your child's skin. And when your child's urine mixes with bacteria from his stool, it breaks down into ammonia, which can be very harsh on the skin. That's why children with frequent bowel movements or diarrhea are more prone to diaper rash.

Colorectal cancer screening tests Screening is the process of looking for cancer in people who have no symptoms of the disease. Several tests can be used to screen for colorectal cancers. These tests can be divided into: Tests that can find both colorectal polyps and cancer: These tests look at the structure of the colon itself to find any abnormal areas. This is done either with a scope put into the rectum or with special imaging (x-ray) tests. Polyps found during these tests can be removed before they become cancerous, so these tests may prevent colorectal cancer. Because of this, these tests are preferred if they are available and you are willing to have them. Tests that mainly find cancer: These tests check the stool (feces) for signs of cancer. These tests are less invasive and easier to have done, but they are less likely to detect polyps.

Ridge splitting with bone expansion is a technique of manipulation of bone to form receptor site for implant without removing any bone from the implant site.

The lymphatic system is a network of specialized vessels (lymph vessels) throughout the body whose purpose is to collect excess lymph fluid with proteins, lipids, and waste products from the tissues. This fluid is then carried to the lymph nodes, which filter waste products and contain infection-fighting cells called lymphocytes. The excess fluid in the lymph vessels is eventually returned to the bloodstream. When the lymph vessels are blocked or unable to carry lymph fluid away from the tissues, localized swelling (lymphedema) is the result.

Cardiogenic shock is a condition in which your heart suddenly can't pump enough blood to meet your body's needs. The condition is most often caused by a severe heart attack. Cardiogenic shock is rare, but it's often fatal if not treated immediately. If treated immediately, about half the people who develop the condition survive.

Teratomas are tumors made up of tissues, such as hair, muscle, and bone. They occur most often in the ovaries in women, and the testicles in men. They may be benign or malignant. Symptoms vary depending on the location. A painful lump or swelling may be apparent. Some babies have a mass that can be seen on an ultrasound before birth. Treatment often involves surgery. In rare cases when a teratoma is malignant, chemotherapy or radiation may be needed.