Muscle twitches and spasms are both uncontrollable muscle movements, but their symptoms, treatment and causes are very different. While a twitch is a minor annoyance you may hardly notice, a spasm occurs quickly, without warning and is typically quite painful. In most cases, neither condition requires medical attention.
A muscle twitch, also called a fasciculation, is uncontrollable movement in a small area of a larger muscle. A twitch can also occur in a specific muscle group that is stimulated by a single nerve. Muscle spasms are also uncontrollable, but involve a muscle that contracts and does not relax.
Muscle twitches may be so minor they’re not noticed, or you may feel a nagging twitch or see the rapid but slight movement under the skin. Twitches are not painful. They may come and go, but do not last for more than a few days. Spasms may be visible as a bulge underneath the skin, they often feel tight and are usually very painful. Spasms typically last from a few seconds to a few minutes.
A muscle twitch may be caused by stress or anxiety, stimulants such as caffeine or they may be a side effect of over-the-counter cold treatments, antipsychotic drugs and medications used to treat asthma or ADHD. Muscle twitching may also be caused by nerve damage, weak muscles and rare but serious conditions such as Lou Gehrig’s disease and muscular dystrophy.
Muscle spasms most often occur as a result of overuse, overstretched or tired muscles. The most common cause of spasms is dehydration, notes the University of Maryland Medical Center. Other causes include low levels of sodium, potassium or calcium, nerve irritation and systemic illnesses such as diabetes, anemia and kidney disease.
Muscle twitching usually stops and does not require treatment. If you’re at risk of being dehydrated due to heat or physical activity, the first step for treating muscle spasms is to consume water or a sports drink. Otherwise, you may treat spasms by gently stretching and massaging the muscle. You may apply heat to the affected muscle to help it relax, but after the spasm stops, use ice to relieve pain. If you have muscle spasms that are especially painful or the soreness doesn't go away, your doctor may prescribe medications to help relieve the tight muscle and the pain.
You won’t be able to prevent a muscle twitch unless it is caused by medication or a physical condition that is treated. However, muscle spasms can often be prevented by regular stretching before exercise, avoiding repetitive muscle movements and staying hydrated with water or sports drinks. You should consult your doctor if you have twitches or spasms that frequently occur or last longer than normal so that potential medical conditions can be ruled out.