Myalgia (muscle pain): Sore muscles, muscle tension, and various causes of muscle pain

The term “myalgia” is a general medical term for muscle pain. It comes from Greek and is used to describe all types of pain and painful conditions affecting the muscles. Muscle pain can occur in a wide variety of diseases and result from a wide range of causes.

The following video provides an overview of the musculature of the human body:

Myalgias are listed in the WHO’s International Classification of Diseases (ICD) under code M79.1.

Broadly speaking, causes can be divided into muscular (originating in the affected muscle itself) and systemic (affecting the entire body) causes.

Muscular causes of myalgia

1. Consequence of overexertion: Sore muscles or muscle tension can be the simplest explanation for myalgia. Overuse during sports or work directly precedes the pain. Poor posture and lack of exercise can also cause muscle tension. This results in severe muscle hardening, often referred to as muscle knots. Since they typically hurt when pressed, doctors also call them trigger points
2. Injuries to the musculoskeletal system: These are usually caused by trauma (such as accidents) and affect both bones (the skeleton) and muscles
3. Inflammation
4. Autoimmune diseases (including rheumatism or multiple sclerosis)

Systemic causes of myalgia

1. Infectious diseases (e.g., the common cold)
2. Metabolic disorders (e.g., “diabetes” = diabetes mellitus or a thyroid disorder)
3. Cancer (tumors)
4. Nervous system disorders (e.g., narrowing in the spinal column, also known as spinal stenosis, which can lead to compression of the spinal cord and radiating pain)
5. Vascular diseases (e.g., peripheral arterial disease, commonly known as “intermittent claudication,” which can lead to a reduction in blood supply to the muscles due to narrowed blood vessels and cause muscle pain during physical activity)

The human body has about 650 muscles. With myalgia, pain can occur in any muscle. © adimas / Fotolia

Can nutritional deficiencies also cause muscle pain?

Nutritional deficiencies or poor diet can also cause muscle pain. Minerals, vitamins, and proteins are particularly important for healthy muscles. Muscles can ache especially when the body lacks magnesium or vitamin D. This is often accompanied by muscle cramps and a feeling of weakness.

A balanced diet and targeted supplementation of missing vitamins and minerals can be a first step in treatment. A high-protein diet can also help treat muscle pain and cramps or prevent them from occurring in the first place. Vegetarians are particularly susceptible to this and should ensure they follow a healthy and balanced diet. However, this does not rule out a vegetarian or vegan diet, as there are plenty of plant-based protein sources (e.g., legumes, nuts, etc.).

Vitamin D deficiency can contribute to the development of myalgia © bit24 / Fotolia

The primary symptom is muscle pain, which can manifest in various ways and take many different forms. This applies both to the location of the pain and to its nature and duration. Depending on the location, medical professionals therefore distinguish between

• locally confined muscle pain, which occurs only at a specific site on the body, and
• diffuse myalgia, which can occur inconsistently—that is, throughout the entire body

Myalgia can present in various forms of pain. Often, the pain resembles muscle soreness.

However, many people also experience the pain in their muscles as

• stabbing
• electric-like, or
• burning.

The spectrum of pain sensations ranges from mild, uncomfortable pain to unbearable pain. The latter cannot be relieved with conventional painkillers.

Muscle pain may

• occur only during physical exertion or
• be constantly present, even at rest.

What additional symptoms are typical of myalgia?

Occasionally, the following symptoms may also be present in myalgia:

• Cramps
• Fatigue
• Dizziness 
• Unsteady gait
• Paralysis
• Weakness and muscle wasting

However, these additional problems and symptoms suggest a systemic cause of the muscle pain, rather than a disease originating in the muscle itself.

As explained in detail above, muscle pain can have many different causes. Therefore, a thorough and comprehensive diagnosis is very important, especially when myalgia is severe or persistent.

The following tests are part of the diagnosis of myalgia:

1. Review of medical history (anamnesis)
2. Physical examination
3. Blood tests (laboratory diagnostics)
4. Ultrasound (sonography)
5. X-ray examination (if bone injuries are suspected or to rule them out)
6. Further diagnostic tests (MRI or CT scan, angiography, etc.)
7. Tissue sampling (muscle biopsy)

Why is the medical history (anamnesis) so important?

The most important task for a physician at the outset and during the diagnostic process is taking the patient’s medical history, which is also referred to among medical professionals as the patient’s anamnesis. Specific events and pre-existing conditions can already provide clues as to the nature of the muscle disorder.

For example, years of tobacco use, multiple heart attacks, or a stroke are already indicative of damage to the blood vessels and should raise suspicion of “peripheral artery disease.” A history of immune system disorders in the patient or among family members may indicate a rheumatic disease.

Taking corticosteroid medications to treat rheumatism can also cause muscle pain or indicate an underlying immunological condition. Therefore, it is advisable to bring a current list of medications to the examination.

What happens during the physical examination?

After a detailed medical history is taken, a thorough physical examination follows. This includes an assessment of the external structure of the skeletal system, followed by palpation of the muscles. In addition, the texture and color of the skin are important and often provide key clues. For example, bruises may indicate accidents, physical trauma, or even coagulation disorders.

During the subsequent examination of the muscles, it is advisable to start well away from the point of maximum pain and work your way toward it slowly. Trigger points, in particular, should be avoided at first. Most patients can already indicate at the start of the examination where their main pain point (i.e., trigger point) is located and are often afraid that the examination will begin there. Therefore, tell the doctor where it hurts the most and ask that the examination not begin there if possible.

You should also mention any diffuse pain that does not occur in a single location. This can be an important clue to a systemic disease as the cause of the muscle pain.

Why is a blood test important?

A complete blood count is recommended for further diagnosis. In particular, an elevated white blood cell count (leukocytes) is important and indicative in this context. Attention should also be paid during the evaluation to any decreased levels of hemoglobin or red blood cells (erythrocytes). A decrease in hemoglobin (anemia) may indicate bleeding into the muscles, but it can also point to other conditions, such as bone marrow damage or cancer.

If metabolic or underlying conditions are suspected, additional laboratory parameters are examined, such as

• blood sugar levels
• thyroid levels
• Kidney function
• Liver function
• coagulation levels
• testing for bacteria, viruses, or parasites, or
• immunological factors.

Is a tissue sample always necessary?

A muscle tissue sample (biopsy) is a so-called invasive diagnostic procedure that interferes with the “integrity” of the body. Therefore, this test is indicated and justified only in cases where a definitive diagnosis cannot be made using non-invasive methods. In the majority of cases, however, a biopsy is not necessary, and a diagnosis can be made based on a physical examination and imaging.

If the muscle pain is caused by muscle soreness, it is usually sufficient to

• a short rest period
• light endurance training, or
• reducing the intensity of your workout.

Applying pain-relieving, circulation-boosting, and cooling ointments (e.g., containing herbal extracts and camphor) can also be soothing.

If rest, cooling, and ointment application are not sufficient, massage can be the next step in the treatment of muscle pain. With trigger points, pressure causes pain to radiate through the shortened muscle bundle. Targeted massage can help release these trigger points. 

The video demonstrates this principle: 

When should muscle pain be treated by a doctor?

You should seek medical treatment if the muscle pain

• occur suddenly (acutely) and without a specific injury
• persists for several weeks
• feels unusual or very severe, and
• is accompanied by other symptoms (nausea, fatigue, fever)

Serious injuries, such as a muscle tear, should be treated specifically. In most cases, rest is necessary; surgical intervention is rarely required. Nevertheless, it is important to rule out concomitant conditions (especially bone fractures) through targeted diagnostic testing.

The medical treatment of muscle pain depends on the specific causes. Therefore, it is important to identify the triggers for muscle pain.

• Postural problems usually require muscle relaxants and physical therapy. This helps to loosen, mobilize, and strengthen the affected body parts.
• For autoimmune diseases, medications such as cortisone or nonsteroidal anti-inflammatory drugs (pain relievers, e.g., known as Voltaren®) are often prescribed.
• Doctors usually treat infections with antibiotics. 

A healthy lifestyle can also help prevent chronic diseases. Therefore, it’s important to eat a balanced diet, drink enough fluids, and exercise. Substances harmful to health should be avoided. But even if a disease is already present, a healthy lifestyle can help alleviate symptoms.

What are the most common causes of muscle pain?

A common cause of acute muscle pain is mechanical overuse, which leads to sore muscles, strains, or muscle tension. Poor posture at work can contribute to chronic myalgia in the neck and back. In addition, viral infections such as the flu can trigger muscle pain throughout the body. Taking certain medications, particularly statins, can also cause muscle pain as a side effect (statin-associated muscle symptoms).

What is the difference between myalgia and myositis?

While myalgia generally describes muscle pain, myositis refers to inflammation of the muscles. This can be caused by pathogens (viral or bacterial infections) or by autoimmune diseases. In cases of muscle inflammation, significant muscle weakness and swelling often occur alongside pain, and blood tests show elevated levels of inflammatory markers and muscle enzymes.

What are the symptoms of fibromyalgia?

Fibromyalgia is a chronic pain syndrome characterized by diffuse muscle pain in various muscle groups (“fibromyalgia”). Those affected also often suffer from sleep disturbances, fatigue, and difficulty concentrating. The pain typically occurs at specific pressure points (tender points). Since there is no inflammatory cause, diagnosis and differential diagnosis for this type of myalgia are often time-consuming.

When should you see a doctor for muscle pain?

If muscle pain after exercise does not subside after a few days, is very severe, or is accompanied by symptoms such as fever, redness, and swelling, it is advisable to see a doctor. Even if muscle pain occurs at rest, is symmetrical throughout the body, or is accompanied by muscle weakness and dark urine, a medical evaluation should be sought urgently to rule out serious muscle disorders or side effects from medications.

Can medications cause muscle pain?

Yes, various medications can cause myalgia as a side effect. The best-known are statins, which are used to lower cholesterol levels. They can range from mild muscle pain to severe muscle breakdown (rhabdomyolysis). Diuretics and cortisone can also cause muscle discomfort or myopathy with long-term use.

How is chronic muscle pain treated?

The treatment of chronic pain often requires a multimodal approach. In addition to medication with pain relievers, physical therapy, heat therapy, and relaxation techniques play a central role in correcting poor posture and relieving muscle tension. In cases of systemic causes, such as hypothyroidism, these must be treated first in order to alleviate the muscle pain.

What role does magnesium play in muscle cramps?

A magnesium deficiency can increase muscle excitability and trigger cramp-like pain or muscle cramps. The body’s need for magnesium is particularly high after physical exertion or heavy sweating. Taking magnesium can help relax the muscles and prevent cramps, but it is not a cure-all for every form of myalgia.

What does mental health have to do with muscle pain?

Stress and psychological strain often lead to unconscious muscle tension, especially in the shoulder and neck area. This persistent tension results in muscle-related pain and stiffness. In addition, mental health conditions such as depression can heighten pain perception, causing muscle pain to feel more intense.