A muscle contraction is a small involuntary contraction caused by a muscle or group of muscles. This minor but uncontrollable contraction is often visible below the skin's surface and may look like a small ripple. Muscle contractions, also called fasciculations, are often triggered by stress and anxiety. These types of repetitive contractions usually occur in areas such as the thumb, eyelid, and calf.
Also described as spasms, a variety of other factors can cause muscle contractions, including fatigue, exercise, dehydration, and dietary deficiency. Muscle twitching can develop after ingesting too much caffeine. An adverse reaction to prescription medications, including estrogen, corticosteroids, and diuretics, can also cause muscle spasms. When a muscle contraction occurs as a result of any of these factors, it is considered benign or harmless, and usually goes away within a few days. Benign muscle contractions are common and do not usually require medical attention.
If a person suspects that their spasms are caused by exercise, caffeine, or anxiety, there are a number of things they can try to reduce or eliminate. You may want to stretch before and after a workout to loosen up your muscles. Eliminating high-caffeine beverages, such as soda and coffee, can also help. To reduce stress, you may want to take a yoga or meditation class. Getting a good night's rest can also help most people.
A muscle twitch that lasts more than a few days could indicate a more serious condition, including a disease or disorder of the nervous system. Diseases that cause muscle spasms include amyotrophic lateral sclerosis, also known as Lou Gehrig's disease; muscular dystrophy; weak muscles or myopathy; and spinal muscular atrophy. A damaged nerve leading to a muscle can also cause a muscle contraction.
In addition to muscle contractions, symptoms that indicate a nerve disorder are weakness; decreased muscle size; and changes in - or loss of - sensation. For long-term muscle contractions, a doctor may need to perform a physical exam to determine the cause. The doctor may also take a medical history to help make an accurate diagnosis.
There are several questions a doctor can ask to help narrow down the cause of persistent muscle contractions. She may ask about which muscles the spasms affect and if they usually occur in the same place. The doctor may want to know how long the jerks last and how often they occur, as well as when the patient first noticed them. Along with medical history, many medical professionals use diagnostic tests to determine the cause and severity of prolonged muscle fasciculation.