The window period is the time from infection until a test can detect any change. The average window period with HIV-1 antibody tests is 25 days for subtype B. Antigen testing cuts the window period to approximately 16 days and nucleic acid testing (NAT) further reduces this period to 12 days.[2] Performance of medical tests is often described in terms of: sensitivity: The percentage of the results that will be positive when HIV is present specificity: The percentage of the results that will be negative when HIV is not present. All diagnostic tests have limitations, and sometimes their use may produce erroneous or questionable results. False positive: The test incorrectly indicates that HIV is present in a non-infected person. False negative: The test incorrectly indicates that HIV is absent in an infected person.

This video: Tennis elbow or lateral epicondylitis is a condition in which the outer part of the elbow becomes sore and tender. The forearm muscles and tendons become damaged from overuse — repeating the same strenuous motions again and again.

The thyroid is a butterfly-shaped gland that sits low on the front of the neck. Your thyroid lies below your Adam’s apple, along the front of the windpipe. The thyroid has two side lobes, connected by a bridge (isthmus) in the middle. When the thyroid is its normal size, you can’t feel it.

This video shows you how to conduct a clinical examination of the shoulder and to identify common causes of pain.

This video clip is part of the FIFA Diploma in Football Medicine and the FIFA Medical Network. To enrol or to find our more click on the following link http://www.fifamedicalnetwork.com

The Diploma is a free online course designed to help clinicians learn how to diagnose and manage common football-related injuries and illnesses. There are a total of 42 modules created by football medicine experts. Visit a single page, complete individual modules or finish the entire course.

The network provides the opportunity for clinicians around the world to meet and share ideas relating to football medicine. Ask about an interesting case, debate current practice and discuss treatment strategies. Create a profile and log on to interact with other health professionals from around the globe.

This is not medical advice. The content is intended as educational content for health care professionals and students. If you are a patient, seek care of a health care professional.

Basic ECG Interpretation Our ECG Interpretation Training and Reference Guides provide basic lessons for ECG analysis as well as a quick reference guide for over 40 types of ECG tracings. The arrhythmia drills and quizzes allow you to practice ECG interpretation. What is ECG Interpretation? An electrocardiogram or ECG, records electrical activity in the heart. An ECG machine records these electrical signals across multiple heart beats and produces an ECG strip that is interpreted by a healthcare professional. How Electrocardiograms Work - ECG Strips To briefly summarize the components of a normal ECG tracings, it consist of waveform components which indicate electrical events during one heart beat. These waveforms are labeled P, Q, R, S, T and U. P wave is the first short upward movement of the ECG tracing. It indicates that the atria are contracting, pumping blood into the ventricles. The QRS complex, normally beginning with a downward deflection, Q; a larger upwards deflection, a peak (R); and then a downwards S wave. The QRS complex represents ventricular depolarization and contraction. The PR interval indicates the transit time for the electrical signal to travel from the sinus node to the ventricles. T wave is normally a modest upwards waveform representing ventricular repolarization. ECG Interpretation illustration spacer image ECG Training - Introduction The focus of this introductory ECG course is to provide a tutorial about the main features of ECGs along with a method for analyzing ECGs. This method includes assessment of rhythm, calculating heart rate, observing P-wave forms, measurement of intervals and segments and the evaluation of other relevant waves. ECG practice exercises serve to reinforce the lesson content.

Scleroderma (skleer-oh-DUR-muh) is a group of rare diseases that involve the hardening and tightening of the skin and connective tissues — the fibers that provide the framework and support for your body. In some people, scleroderma affects only the skin. But in many people, scleroderma also harms structures beyond the skin — such as blood vessels, internal organs and the digestive tract. Signs and symptoms vary, depending on which structures are affected. Scleroderma affects women more often than men and most commonly occurs between the ages of 30 and 50. While there is no cure for scleroderma, a variety of treatments can ease symptoms and improve quality of life.

As a curious child, you might remember staring at an older relative's thick stockings at the blue, gnarled veins lying under the skin like bumpy snakes. Known as varicose veins, these blood vessels, which return blood from the legs to the heart, are actually a more superficial system. The real, working venous system for the legs lies deeper, says to Robert A. Weiss, MD, assistant professor of dermatology at the Johns Hopkins School of Medicine in Baltimore. This is good news, because it means that if the surface veins begin to clump up and bulge, they can be removed or destroyed without ruining circulation to the leg. The National Institutes of Health estimates that 60% of all men and women suffer from some form of vein disorder. A quarter of varicose vein sufferers are men, although Weiss notes that it is almost always women who seek help for spider veins.

Premature ventricular contractions (PVCs) are extra, abnormal heartbeats that begin in one of your heart's two lower pumping chambers (ventricles). These extra beats disrupt your regular heart rhythm, sometimes causing you to feel a flip-flop or skipped beat in your chest.

Neurogenic shock is a distributive type of shock resulting in low blood pressure, occasionally with a slowed heart rate, that is attributed to the disruption of the autonomic pathways within the spinal cord. It can occur after damage to the central nervous system such as spinal cord injury.

Here we’ll explain the symptoms of pancreatitis, how alcohol causes the condition and the other health problems it can lead to. You probably don’t pay much attention to your pancreas. But that small, tadpole-shaped organ behind your stomach and below your ribcage is pretty important. It produces two essential substances: digestive juices which your intestines use to break down food, and hormones that are involved in digestion, such as insulin, which regulates your blood sugar levels. Pancreatitis is when your pancreas becomes inflamed and its cells are damaged. Heavy drinking can cause pancreatitis. But if you drink within the government’s low risk unit guidelines, you should avoid upsetting this important organ.

Ten percent of all pregnancies are complicated by hypertension. Eclampsia and preeclampsia account for about half of these cases worldwide, and these conditions have been recognized and described for years despite the general lack of understanding of the disease. [1] In the fifth century, Hippocrates noted that headaches, convulsions, and drowsiness were ominous signs associated with pregnancy. In 1619, Varandaeus coined the term eclampsia in a treatise on gynecology. [2, 3]

You get motion sickness when one part of your balance-sensing system (your inner ear , eyes, and sensory nerves) senses that your body is moving, but the other parts don't. For example, if you are in the cabin of a moving ship, your inner ear may sense the motion of waves, but your eyes don't see any movement.

A facet joint injection is a relatively simple, straightforward procedure, and is usually performed in an office based procedure suite or in an ambulatory surgical center. As with many spinal injections, facet joint injections are best performed using fluoroscopy (live X-ray) for guidance to properly target and place the needle (and to help avoid nerve injury or other injury).

Reconstruction of a shoulder separation or acromio-clavicular dislocation.

Ultrasound or ultrasonography is a medical imaging technique that uses high frequency sound waves and their echoes. The technique is similar to the echolocation used by bats, whales and dolphins, as well as SONAR used by submarines. In ultrasound, the following events happen: The ultrasound machine transmits high-frequency (1 to 5 megahertz) sound pulses into your body using a probe. The sound waves travel into your body and hit a boundary between tissues (e.g. between fluid and soft tissue, soft tissue and bone). Some of the sound waves get reflected back to the probe, while some travel on further until they reach another boundary and get reflected. The reflected waves are picked up by the probe and relayed to the machine. The machine calculates the distance from the probe to the tissue or organ (boundaries) using the speed of sound in tissue (5,005 ft/s or1,540 m/s) and the time of the each echo's return (usually on the order of millionths of a second). The machine displays the distances and intensities of the echoes on the screen, forming a two dimensional image like the one shown below.

The menstrual cycle is the regular natural change that occurs in the female reproductive system like the uterus and ovaries that make pregnancy possible. The cycle is required for the production of ovocytes, and for the preparation of the uterus for pregnancy.

Effect of smoking,it's very dangerousAfter watch this video I hope smoker stop smoke now it is dangerously for human

The usual reason given for people getting fat is that they eat too much and/or exercise too little. That reflects one of the basic laws of thermodynamics—I forget which one. The amount of energy you put into a system minus the energy you take out has to be stored somewhere i.e. FAT! This formulation—true though it is—does not entirely explain obesity since some people seem to eat more than fat people and exercise no more than these same fat people, and yet they are not fat! Chalking this fact up to the general perversity of the universe is not sufficient explanation. Other factors must come into play. I mention below some of the ideas thoughtful people have proposed to explain why fat people become fat:

The superior sagittal sinus (also known as the superior longitudinal sinus), within the human head, is an unpaired area along the attached margin of falx cerebri. It allows blood to drain from the lateral aspects of anterior cerebral hemispheres to the confluence of sinuses.