Dr. Mark H. Joyner M.D.

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...

What is creatine phosphokinase (CPK)?Creatine phosphokinase (CPK) is an enzyme, which is predominantly present in the heart, brain, and skeletal muscles. Converting creatine into phosphate is the main task of this enzyme. The cells of the body then quickly consume or burn this phosphate and use it...

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,...

Almost every cell in the body has a primary source of energy, which is usually glucose. However, when the body doesn't have enough glucose, the liver responds by producing chemicals known as ketones, converting stored fatty acids into ketone bodies. Ketones are used as a backup fuel source when...

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...

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...