Having an itchy muscle is the sensation of an itch that’s not on the surface of the skin but is felt deep under the skin in the muscle tissue. It’s usually present without any rash or visible irritation. This can happen to anyone, though certain conditions make people more prone to it. It’s especially common in runners.

Scientists are studying itch (also called pruritus) and its relationship to neural health and pain. Itchy muscles are not actually muscle tissues that want to be scratched but nerves in the muscles sending the wrong signal. It may also be related to how nerves respond to increased blood flow during exercise and warm temperatures.

Itchy muscles aren’t dangerous, however they may be a symptom of another health issue. You should talk with a doctor about any potential causes if the feeling persists or recurs.

If you’re pregnant and you suddenly get itchy, you might have a serious liver condition. Talk with a doctor if you have any other signs of allergic reaction.

We don’t know exactly why muscles itch, but there are a number of potential causes and correlations. It’s easier to determine a cause if you have other symptoms, but often itchy muscles are an isolated sensation.

The nervous system has receptors that respond to stimuli (like heat, cold, pain, and itching) and tell your body how to respond to protect itself. Scientists are researching neurological conditions and what causes nerves to respond the way they do.

An increasing number of studies are finding overlap in the neural responses of pain and itchiness. This could result in breakthroughs for treating both chronic pain and itching.

Fibromyalgia

Fibromyalgia is a chronic condition with unknown cause that affects the muscles. The pain and fatigue in muscles from fibromyalgia may also cause muscle itch. Other symptoms of fibromyalgia include unexplained pain and weakness.

Chronic fatigue syndrome

Recent research found a potential cause for some symptoms of chronic fatigue syndrome (CFS). People with CFS may experience:

  • dizziness
  • itching
  • digestion problems
  • chronic pain
  • bone and joint problems.

Scientists found these symptoms linked to a single gene in people with CFS and their family members. The itching caused by CFS is more likely to be skin-level and not in the muscles. However, CFS affects muscles too, and when they’re exhausted, it’s possible they may itch.

Multiple sclerosis

Itching is one of the abnormal sensations that may come with multiple sclerosis (MS). Related symptoms include burning, stabbing pain, and a “pins and needles” sensation. MS is a disease in the central nervous system, so it can cause the feeling of itchiness deep in the muscles even if there’s nothing else causing the itch.

Neuropathic Itch

Damage to the nervous system can cause a desire to itch for no apparent reason. Conditions like stroke, multiple sclerosis, shingles, and cavernous hemangioma can cause neuropathic itch because they affect many neural pathways. Because neuropathic itch is hard to locate, it may be experienced as an itch deep in the muscle.

One study found that itching could be triggered by problems with brain connectivity. This contributes to the growing body of science that aims to better understand how nerves and neural health affect itching.

Itchy muscles during and after workout

If your itching only happens when you exercise, you likely won’t have any other symptoms.

People complain of itchy muscles especially in warm weather or if it’s been a while since they last exercised. Exercising, especially cardio workouts like running and walking, increase your blood flow and send a lot of oxygen to your muscles. The theory is that the blood vessels in your muscles are stretching beyond what they’re used to, and this wakes up the nerves around them.

One animal study found that mice have an important nerve receptor that links muscle contraction as well as signaling itch.

Since the nerve signals that communicate pain are closely linked with the nerve signals for itch, itching muscles could also be a way that your body is processing stress from working out.

Vasculitis is inflammation of blood vessels, and case studies have shown that exercise can cause it. When your blood vessels are inflamed, the vessel walls change and can restrict blood flow. All of this may send signals to the nerves in your muscles and cause your muscles to itch.

None of this has been proven, but itchy muscles are a common experience among runners.

Medication

It could be that one of your regular medications or supplements is causing the itch. Ask a doctor about all potential side effects of your medication, including interactions between medications if you take multiple.

In pregnancy

Itching during pregnancy could be simply due to all of the stretching your body does to grow and carry your baby. But it could also be a symptom of intrahepatic cholestasis of pregnancy (ICP). ICP is a liver condition that may pose risks to you and your baby. It’s most common in the third trimester. Talk with a doctor right away if you have any signs of ICP.

Exercise-induced anaphylaxis

In rare cases, people can actually have an allergic reaction to exercise. Exercise-induced anaphylaxis can include itching as well as rash and trouble breathing.

Itchy muscles treatment | Treatment

How you treat itchy muscles will depend entirely on the cause. A doctor should assess cases of severe and persistent itch. The main goal of treating itchy muscles is to reduce the urge to scratch without causing any harm to the muscles or skin.

At-home remedies

Mild and infrequent cases of itchy muscles can be treated at home.

Try the following:

  • Massage with a gentle, fragrance-free lotion.
  • Take a cool shower or bath to slow blood flow.
  • Meditate to calm your mind and disassociate from the itch sensation.
  • Try the legs up the wall yoga pose for recovery after running.
  • Apply ice to numb the sensation.
  • Capsaicin cream is an over-the-counter cream that may provide relief.
  • Acetaminophen (Tylenol) may reduce muscle inflammation and therefore reduce itching.

Medical treatment

If you have a chronic condition that causes muscle itch, a doctor can help create a treatment plan.

In some cases, antidepressants, anti-anxiety medication, and antihistamines may help.

Local anesthesia has been used to dull the nerves in cases of neuropathic itch.

Some unsubstantiated evidence suggests reflexology may improve body systems, which could benefit your nerves and prevent itch.

Call your doctor if your itching comes with:

  • rash
  • nausea
  • diarrhea

Call 911 or get emergency help if you have these signs of a severe allergic reaction:

  • scratchy throat
  • trouble breathing
  • panic or anxiety
  • difficulty swallowing
  • dizziness
  • heart palpitations

Itchy muscles is a common sensation that may or may not be related to a more general health concern. It usually has more to do with nerves and blood flow than an actual itch.

If you have extreme or persistent itching, especially if it’s related to other changes in your health, it’s important to work with a doctor to find the cause and get treatment.