What causes muscle aches?

After unfamiliar exercise, small areas of muscle irritation can cause soreness that eases with rest. Viral illnesses such as Influenza or COVID-19 can produce more widespread aches alongside fever, tiredness, cough or other symptoms. Heat exposure may lead to painful muscle tightening, while persistent, widespread pain and poor sleep can occur with Fibromyalgia. Long COVID may be considered when aches continue after an earlier infection.

Less commonly, muscle aches accompany an underactive thyroid, malaria or Dengue Fever. The timing, affected areas, medicines, travel and associated symptoms help a clinician narrow the cause.

Pause strenuous activity, drink fluids regularly and try gentle movement once it is comfortable. A warm shower or wrapped heat pack may relax a tight area. Use pain medicine only if it is suitable for you and follow the label; check with a pharmacist if you take other medicines or have kidney, liver or stomach problems. Avoid intense exercise while feverish or unwell.

Arrange an assessment when aches are severe, keep returning, last beyond expected recovery, or come with weakness, joint swelling, a rash, dark urine or unexplained weight change. Seek urgent care for breathing difficulty, chest pain, confusion, inability to walk, severe dehydration, or a high fever with marked illness. Mention recent travel to a malaria area or mosquito exposure when relevant.

Ask whether the pattern fits muscle strain, infection, heat illness or an underlying condition. Tell the clinician when the aches began, what activity or illness preceded them, where they are located, and which medicines or supplements you use. Ask whether an examination or blood tests are appropriate.