Muscle pain (myalgia)
Aching, sore or tender muscles. Most often it is from exercise, overuse or a viral illness and settles on its own, but widespread or persistent muscle pain can reflect a statin side effect, an underactive thyroid, low vitamin D, or specific rheumatological conditions.
What it means
Muscle pain (myalgia) is a very common symptom, ranging from a single overused muscle to aching all over. Most muscle pain is benign and self-limiting: exercise and overuse (delayed muscle soreness), minor injury, or the generalised aches of a viral infection like flu. When muscle pain is more widespread, persistent or unexplained, a wider range of causes is considered. Medications are important — statins (cholesterol-lowering drugs) commonly cause muscle aches, and rarely significant muscle damage. Medical causes include an underactive thyroid (which causes aches, cramps and stiffness), vitamin D deficiency (diffuse muscle and bone pain), fibromyalgia (widespread pain with fatigue and poor sleep, where tests are normal), and, in older adults, polymyalgia rheumatica (marked stiffness and pain in the shoulders and hips with a raised ESR). The most urgent scenario is severe muscle pain and weakness with dark, cola-coloured urine, which can signal serious muscle breakdown (rhabdomyolysis).
Common causes
- Exercise, overuse or minor injury — the commonest cause; localised and self-limiting.
- Viral infections — generalised aches with flu and other illnesses.
- Statins and some other medications — a common cause of muscle aches; rarely significant damage.
- Hypothyroidism — aches, cramps and stiffness, with tiredness.
- Vitamin D deficiency — diffuse muscle and bone pain.
- Fibromyalgia — widespread pain with fatigue and poor sleep; tests normal.
- Polymyalgia rheumatica — older adults; shoulder and hip stiffness with a high ESR.
- Rhabdomyolysis (serious) — severe pain and weakness with dark urine.
Lab work-up approach
Localised muscle pain from exercise or a viral illness needs no tests. For widespread, persistent or unexplained muscle pain, a targeted panel helps: creatine kinase (CK) for muscle damage (important with statins or marked weakness), TSH for an underactive thyroid, vitamin D for deficiency, and CRP/ESR (a markedly raised ESR in an older adult with shoulder and hip stiffness points to polymyalgia rheumatica). A medication review, especially for statins, is essential. Mediora.AI surfaces the CK, thyroid, vitamin D and inflammatory pattern from your results to help narrow the cause; the interpretation and any medication change belong with your doctor.
Tests Mediora.AI can interpret
Related conditions
Panels to consider
When to see a doctor
Muscle pain from exercise or a passing illness just needs rest, fluids and simple pain relief. See a doctor if muscle pain is widespread, persistent, or unexplained, comes with muscle weakness, or is affecting daily life — especially to check for a treatable cause like thyroid disease, vitamin D deficiency or a medication effect. If you take a statin and develop significant muscle aches or weakness, raise it with your doctor (don't stop it yourself). Seek urgent care for severe muscle pain and weakness with dark, cola-coloured urine, which can indicate serious muscle breakdown, and for new shoulder and hip stiffness with feeling unwell in an older adult. Mediora.AI helps screen the muscle, thyroid and vitamin D contributors; persistent muscle pain is assessed by your doctor.