Muscle spasms and twitches are usually due to benign causes; however, there are conditions that may present with only twitches or spasms and can have serious consequences if not identified and managed.
Calcium
Changes in a patient’s blood calcium level, either high or low, may lead to muscle twitching or spasms. This is often an early sign of abnormal calcium levels. If the calcium level is not corrected, it may worsen and lead to more severe consequences eg seizure or a heart attack. Causes of calcium changes include parathyroid disease, medications, pancreatitis and cancer.
Kidney disease
Chronic kidney disease can lead to changes in calcium levels. Normally, calcium levels are controlled via hormones acting on the kidney, intestine and bone. The parathyroid gland senses a low blood calcium level and this causes a release of a hormone (parathyroid hormone). This hormone acts on 3 areas to increase calcium including on the kidney to both reduce excretion of calcium and to increase an enzyme associated with vitamin D (leading to an increased absorption from the gut). Patients with kidney disease have a reduced ability to do this and therefore are prone to hypocalcaemia. These patients may present with early symptoms of hypocalcaemia eg twitching and generalised weakness.
Vascular disease
We ask about severe pain, colour change, inability to walk short distances and waking in the night with muscle pain to capture patients who have a vascular problem in their leg. This is when there is a narrowing in the artery supplying their leg meaning less blood and therefore less oxygen can supply the muscles.
- This pain occurs on exertion as the muscle has a higher demand for oxygen when exercising and this cannot be reached as the blood supply is already at the maximum
- Night-time pain that is relieved by hanging their leg over the bed can be due to this problem as gravity helps with blood flow to the patient’s legs.
The pain due to a narrowing in the artery is called ‘claudication’ and needs treatment in order to maintain the blood supply to the limb over time.
If there is a sudden blockage in the artery due to a clot this must be immediately treated. This is because there is no oxygen getting to the muscle and the muscle will die if the artery is not reopened. This is why we send patients to A&E if constant + current severe pain.
Medication adverse effects
Medications can cause muscle spasms/twitches due to interactions with other medications or if the dose is too high/too low. If a medication has recently been started and no other changes in circumstance, it is likely that the medication is the culprit and the best clinician to first review the patient is the Pharmacist.