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Weakness that keeps getting worse

Also called: Progressive weakness, worsening muscle weakness, losing strength

Weakness that keeps getting worse over weeks or months is different from feeling tired. It means real loss of strength, like trouble climbing stairs, lifting things, or holding your head up. It can come from nerve, muscle, or thyroid problems and should be checked. Weakness that affects breathing or swallowing is an emergency.

Common causesNerve or muscle diseases, thyroid problems, medicines, myasthenia gravis
Usually serious?Can be; worsening weakness needs prompt checking
Get checked ifAlways; urgently if it affects breathing or swallowing
If you think it's an emergency, call 911.Thinking about suicide? Call or text 988.

Overview

Weakness is reduced strength in one or more muscles. You may notice it climbing stairs, getting up from a chair, lifting your arms over your head, gripping, or walking. Weakness that's in one area is more noticeable than weakness all over.

When weakness slowly gets worse, it may be from a muscle disease, a nerve disease, a problem where nerves meet muscles (like myasthenia gravis), a thyroid problem, or a medicine side effect. Some of these are very treatable, so early diagnosis matters.

When to get medical care

Call 911Weakness with trouble breathing, swallowing, or speaking. Sudden weakness on one side of the body (possible stroke). Weakness that is quickly spreading up from the legs (possible Guillain-Barré syndrome). Loss of bladder or bowel control with leg weakness.
Get care todayWeakness that is getting worse over days. Weakness with drooping eyelids, double vision, or trouble chewing. Weakness with severe muscle pain or dark urine.
See a doctor soonWeakness that keeps getting worse over weeks or months. Weakness with muscle twitching or muscles that look smaller. Trouble climbing stairs, rising from a chair, or lifting your arms. Weakness that started after a new medicine. Weakness with a rash, weight loss, or tiredness.

Causes

Causes include muscle diseases (like polymyositis, dermatomyositis, and muscular dystrophy), myasthenia gravis, nerve diseases (like ALS, peripheral neuropathy, and chronic inflammatory demyelinating polyneuropathy), multiple sclerosis, pinched nerves or spinal cord compression, thyroid problems, low potassium or other mineral problems, Addison disease, medicines like statins and steroids, alcohol, and, less often, cancer.

OwieClear has pages on 5 conditions that can cause weakness that keeps getting worse. Each shows how soon to get care.

Common causes

Less likely causes

  • Peripheral neuropathySee a doctor if it doesn't get better

    Damage to the nerves in the feet and hands, often from diabetes, low vitamin B12, or alcohol.

  • Multiple sclerosis (MS)See a doctor if it doesn't get better

    A condition where the immune system damages the coating around nerves in the brain and spinal cord.

What you can do at home

  • See a doctor for weakness that keeps getting worse. Home care can't fix the cause.
  • Keep a diary of what tasks are getting harder and when.
  • Stay as active as is safe, and ask about physical therapy to keep muscles working.
  • Prevent falls: use handrails, remove tripping hazards, and use a cane or walker if needed.
  • Rest during the day if weakness gets worse with activity.
  • Don't stop any medicine without talking to your doctor, even if you think it's the cause.

Medicines

Treatment depends on the cause. A doctor may prescribe medicines for myasthenia gravis, thyroid disease, or inflammatory muscle diseases, change medicines that cause weakness, or refer you to physical therapy or a neurologist.

At the doctor

The doctor will find whether the weakness comes from the muscles, nerves, or another cause.

Questions you may be asked

  • When the weakness started and how fast it's getting worse
  • Which muscles are weak, and whether it's one side or both
  • Whether it's worse with activity and better with rest
  • Drooping eyelids, double vision, trouble swallowing or breathing
  • Numbness, twitching, cramps, or muscle loss
  • Your medicines and family history

The exam

A physical and nerve exam, testing strength, reflexes, feeling, and muscle size.

Tests

  • Blood tests, including muscle enzymes (CK), thyroid, and electrolytes
  • EMG and nerve conduction studies
  • An MRI of the brain or spine
  • Antibody tests for myasthenia gravis
  • A muscle biopsy in some cases

Prevention

You can't prevent most causes, but early diagnosis helps.

  • See a doctor early for weakness that's getting worse
  • Keep active to maintain strength
  • Review medicines with your doctor

Check your symptoms

Most symptoms have more than one possible cause. The symptom checker looks at all of your symptoms together, plus your age, and shows how soon to get care.

Start the symptom checker

Sources

Last updated 2026-11-13.