Why Do My Muscles Ache? Causes and Muscle Pain Relief

Aching muscles are something almost everyone experiences, whether after a new exercise class, a long day at a desk or a bout of flu. Most muscle aches are harmless and settle within days. When they keep coming back, or appear for no obvious reason, it is worth looking for a cause.

This guide explains why your muscles might ache, how to get relief, why muscles can ache all the time and when muscle pain needs medical attention.

When to see someone: see your GP promptly if aches are widespread, come with fever, weakness or dark urine, or started after a new medicine such as a statin. For aches after training or long hours at a desk, sports massage in Chiswick can ease tight muscles. Sessions start from £65. Book online or call 020 4515 0000.

Quick answer

Muscles usually ache because of exercise or overuse, tension from stress or posture, poor sleep, dehydration or a viral illness such as a cold, flu or COVID. Some medicines, particularly statins, low vitamin D and an underactive thyroid can also cause aching. For relief, keep gently active, use heat, stretch, drink enough fluids and use simple painkillers if suitable. Muscle aches with dark urine after intense exercise, a fever and stiff neck, or unexplained weakness need urgent medical attention.

Why do my muscles ache?

• Exercise and overuse. Delayed onset muscle soreness starts 12 to 24 hours after unfamiliar or hard exercise and peaks at one to two days.
• Tension and posture. Long periods at a desk, carrying heavy bags and stress keep muscles tight.
• Poor sleep. Sleep is when muscles recover, and poor sleep increases pain sensitivity.
• Viral illness. Colds, flu and COVID commonly cause aching all over.
• Dehydration and not eating enough, especially around exercise
• Minor strains from lifting or sport

Why do my muscles ache all the time or for no reason?

Muscles that ache most days, or all over, are more likely to have a medical cause worth checking:

• Medicines, especially statins. Do not stop them without speaking to your GP
• Low vitamin D, which is common in the UK in winter
• An underactive thyroid. See underactive thyroid symptoms
• Fibromyalgia, which causes widespread pain, fatigue and poor sleep. See how fibromyalgia is diagnosed
• Polymyalgia rheumatica, which causes pain and stiffness in the shoulders and hips, usually in people over 50
• Chronic fatigue syndrome, long COVID and recovery from viral illness
• Stress, anxiety and depression, which can all increase muscle pain

When muscles feel sore without exercise or an obvious illness, think back over the last few weeks: a new medicine, a recent virus, a run of poor sleep, more stress or more hours at a desk are the most common explanations. If none fit and the aching continues for more than two weeks, see your GP. If you would like to check two common causes privately, Omnia offers a vitamin D blood test (£59) and a thyroid blood test (£59) with no GP referral needed.

Upper arm muscle pain, including the left arm

Pain in the muscle at the top of the arm, on either side, is usually caused by a strain from lifting, the gym or a repetitive task, by sleeping on that arm, or by soreness after a vaccination, which normally settles within a couple of days. Shoulder problems such as rotator cuff tendinopathy are often felt in the outer upper arm rather than the shoulder itself, and an irritated nerve in the neck can cause arm pain with pins and needles. See shoulder and arm pain and left shoulder pain.

Call 999 if left arm pain comes with chest pain or tightness, breathlessness, sweating or feeling sick, as this can be a heart attack.

Muscle pain in the bottom

An ache deep in the buttock muscles can come from a gluteal strain, long periods of sitting, or tightness in the piriformis muscle, which lies close to the sciatic nerve. Pain that spreads down the back of the leg with tingling is more likely to come from the lower back. See piriformis syndrome exercises and sciatica exercises.

How to relieve muscle aches

• Keep moving gently. Light walking and stretching help more than complete rest.
• Use heat. A warm bath, shower or heat pack relaxes tight muscles.
• Ice can help in the first day or two after a strain.
• Drink enough fluids and eat regular meals with enough protein.
• Take simple painkillers such as paracetamol or ibuprofen if suitable, or use an anti-inflammatory gel.
• Massage. Massage reduces exercise-related soreness and eases tension.
• Sleep well to give muscles time to recover.
• Build training gradually to prevent soreness next time.

When to seek medical help

Call 999 if you have:

• Muscle aches with a fever, stiff neck, severe headache, sensitivity to light or a rash that does not fade when a glass is pressed on it
• Sudden muscle weakness with difficulty breathing or swallowing

Get same-day medical advice, from your GP or NHS 111, if:

• You have severe muscle pain and weakness with dark or brown urine, especially after intense exercise
• You are over 50 and have new pain and stiffness in both shoulders or hips, especially with a headache or jaw pain
• One calf is painful, swollen, warm or red

See your GP if:

• Muscle aches have lasted more than two weeks without a clear reason
• Aches started after a new medicine, such as a statin
• You also feel very tired, have lost weight or feel generally unwell
• You notice muscle weakness

Frequently asked questions

Why do my muscles ache after exercise?

This is delayed onset muscle soreness, a normal response to unfamiliar or harder exercise. It settles within a few days and becomes less severe as you adapt. Our guide to red light therapy for muscle recovery looks at what the research shows for exercise soreness.

Can stress make your muscles ache?

Yes. Stress keeps muscles tense, particularly in the neck, shoulders and back, and increases sensitivity to pain.

Can dehydration cause muscle aches?

Dehydration can contribute to muscle cramps and aches, especially during hot weather or exercise.

Should I exercise with aching muscles?

Light activity usually helps muscle soreness. Avoid hard exercise if aches come with a fever or feeling unwell.

Muscle pain treatment in Chiswick

Muscle pain is assessed and treated at Omnia Lifestyle, 8 to 9 Bedford Corner, The Avenue, Chiswick W4 1LZ, close to Turnham Green station, on bus routes 94, E3 and 272. Limited parking is available on request when booking. We look at your work, training, sleep, stress and medicines, assess how you move and may combine massage, physiotherapy, red light therapy, acupuncture or compression therapy, suggesting blood tests or a GP review if a medical cause is possible.

• Sports massage or deep tissue massage: from £65 for 30 minutes or £90 for 60 minutes, for exercise soreness and tension.
• Physiotherapy: initial assessment and treatment, 70 minutes, £99, with an HCPC-registered physiotherapist, for pain that keeps returning or limits movement.
• Red light therapy: NovoTHOR full-body session, 20 minutes, £70.
• Acupuncture: traditional acupuncture, 60 minutes, £80.

Read more about muscle pain and fibromyalgia, see deep tissue vs sports massage and soft tissue injury healing times, explore manual therapy, physiotherapy and red light therapy, or book an appointment.

This article is general information, not medical advice. If you have any of the warning signs listed above, seek medical attention.