Frostbite is an injury caused by freezing of the skin and underlying tissues. First your skin becomes very cold and red, then numb, hard and pale. Frostbite is most common on the fingers, toes, nose, ears, cheeks and chin. Exposed skin in cold, windy weather is most vulnerable to frostbite. But frostbite can occur on skin covered by gloves or other clothing.

Norepinephrine is synthesized from dopamine by dopamine β-hydroxylase.[7] It is released from the adrenal medulla into the blood as a hormone, and is also a neurotransmitter in the central nervous system and sympathetic nervous system where it is released from noradrenergic neurons.

A chalazion is a lump of the lid that is caused by obstruction of the drainage duct of an oil gland within the upper or lower eyelid. This lump may increase in size over days to weeks and may occasionally become red, warm, or painful.

A spider nevus is a collection of small, dilated arterioles (blood vessels) clustered very close to the surface of the skin. The cluster of vessels is web-like, with a central spot and radiating vessels.

What is systemic lupus erythematosus? The immune system normally fights off dangerous infections and bacteria to keep the body healthy. An autoimmune disease occurs when the immune system attacks the body because it confuses it for something foreign. There are many autoimmune diseases, including systemic lupus erythematosus (SLE). The term lupus has been used to identify a number of immune diseases that have similar clinical presentations and laboratory features, but SLE is the most common type of lupus. People are often referring to SLE when they say lupus.

Take your left leg and place your ankle against the knee. Hold the position for a moment before changing legs. This helps stretch the tiny piriformis muscle, which sometimes becomes inflamed and presses against the sciatic nerve causing pain. Repeat by switching sides and doing the same exercise with the other leg.

The 12-lead ECG is a vital tool for EMT’s and paramedics in both the prehospital and hospital setting. It is extremely important to know the exact placement of each electrode on the patient. Incorrect placement can lead to a false diagnosis of infarction or negative changes on the ECG.

Knee replacement surgery advances are improving patients' experiences and outcomes. Knee surgery -- or even partial knee replacement -- is often the solution for advanced knee arthritis. Today you can regain significant mobility and flexibility after knee replacement thanks to advances in orthopedic surgery technology, materials and techniques. Knee replacement recovery times also have improved. This knee replacement surgery video covers what you can expect out of these knee joint replacement advances. Knee replacement surgery has been around for more than 30 years and is an incredibly successful operation. In the past the past, when a person had bad arthritis of the knee, they were pretty much out of luck other than taking aspirin. They'd be debilitated and limited in their activities. So, when a person has pain, stiffness, and their life is becoming restricted by that, that's when it's time to consider knee replacement. We always do non-surgical treatment first. When that doesn't work anymore, then it's time to consider knee replacement. About 500,000 a year are done, and most patients who have gone through this basically say that they wish they had done it sooner.

With the help of vitamin K, the liver produces proteins that are important in blood clotting. It is also one of the organs that break down old or damaged blood cells. The liver plays a central role in all metabolic processes in the body. In fat metabolism the liver cells break down fats and produce energy.

The heart receives its own supply of blood from the coronary arteries. Two major coronary arteries branch off from the aorta near the point where the aorta and the left ventricle meet. These arteries and their branches supply all parts of the heart muscle with blood.

A C-reactive protein (CRP) test is a blood test that measures the amount of a protein called C-reactive protein in your blood. C-reactive protein measures general levels of inflammation in your body. High levels of CRP are caused by infections and many long-term diseases.

The essential components of the human cardiovascular system are the heart, blood and blood vessels. It includes the pulmonary circulation, a "loop" through the lungs where blood is oxygenated; and the systemic circulation, a "loop" through the rest of the body to provide oxygenated blood.

Try these tips from top fertility experts to increase the odds you'll be prego ASAP…that is, if you want to be. Take Prenatal Vitamins. ... Try to Time It. ... Skip the Lube. ... Cut Back on Caffeine. ... Don't Increase Your Exercise Routine. ... Go Easy on the Alcohol. ... Try to Chill Out.

Work out the length of your average menstrual cycle. Day one is the first day of the menstrual period and the last day is the day before the next period begins. Ovulation happens about two weeks before the next expected period. So if your average menstrual cycle is 28 days, you ovulate around day 14.

Anaphylaxis is a severe, potentially life-threatening allergic reaction. It can occur within seconds or minutes of exposure to something you're allergic to, such as a peanut or the venom from a bee sting. The flood of chemicals released by your immune system during anaphylaxis can cause you to go into shock; your blood pressure drops suddenly and your airways narrow, blocking normal breathing. Signs and symptoms of anaphylaxis include a rapid, weak pulse, a skin rash, and nausea and vomiting. Common triggers of anaphylaxis include certain foods, some medications, insect venom and latex. Anaphylaxis requires an immediate trip to the emergency department and an injection of epinephrine. If anaphylaxis isn't treated right away, it can lead to unconsciousness or even death.

Non-Hodgkin's lymphoma, also called non-Hodgkin lymphoma, is cancer that originates in your lymphatic system, the disease-fighting network spread throughout your body. In non-Hodgkin's lymphoma, tumors develop from lymphocytes — a type of white blood cell. Non-Hodgkin's lymphoma is more common than the other general type of lymphoma — Hodgkin lymphoma. Many different subtypes of non-Hodgkin's lymphoma exist. The most common non-Hodgkin's lymphoma subtypes include diffuse large B-cell lymphoma and follicular lymphoma.

Educational video describing injection techniques for painful conditions of the foot and ankle.