Dr. John S Leung MD

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...

Uncontrollable shivering is characterized by the rapid shifting between muscle relaxation and contraction. It is through these contractions that the body warms itself up when exposed to cold. Shivering is not always accompanied by fever. In some cases, shivering may occur before the onset of...

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 epistaxis?Epistaxis or commonly called a nosebleed is defined as a type of bleeding that occurs from the nostrils, the nasal cavity, or the nasopharynx. Nosebleeds are mostly caused by the rupture of blood vessels inside the nose. Bleeding may be spontaneous or caused by injuries or trauma....

Humans have approximately 60 percent of water in the body. Even if 1.5-2 percent of that water is lost, mild dehydration will start, which can lead to severe dehydration requiring immediate medical attention. Because your mood, energy level, and coordination deteriorate with the loss of body fluids,...

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...