Dr. John S Leung MD

OverviewA transient ischemic attack (TIA) is a mini-stroke, which only lasts for a few minutes. It occurs when blood stops flowing to a part of the brain for a short time. The symptoms of TIA are similar to other symptoms of stroke, but they do not last long, so TIA does not lead to permanent...

IntroductionThe only way to prevent serious and life-threatening diseases such as meningitis is through vaccination. Meningitis can also be caused by viral, bacterial, and fungal infections. The infection usually affects the meninges or membranes that enclose the brain and spinal cord. Although...

What is lightheadedness?Lightheadedness or feeling faint may not always be a cause for concern. However, it may also indicate an underlying health problem and can increase the risk of falling and fall-related injuries. If you feel lightheaded, drink water or fluids containing electrolytes and take...

Leukocyte Esterase Urine TestLeukocyte esterase (LE) is an esterase produced by white blood cells (WBCs) or leukocytes. A leukocyte esterase test is a urine test used to detect the presence of white blood cells and other health conditions associated with infection.Normally, leukocyte esterase...

What is encephalitis?Encephalitis means inflammation of the brain. Fever, headache, and joint pain are often experienced in the early stages of encephalitis. Other severe symptoms may develop over some days or hours. They include personality changes, seizures, disorientation, confusion, or...

Doctors or physicians are categorized according to different factors including medical specialties and subspecialties. Most doctors specialize in a specific area of medicine. This article provides a summary of the different types of doctors in the medical field. AllergistsAllergists are also...