Myalgia Definition

Myalgia is a medical term for muscle pain. The word is also widely used, often erroneously, by the non-medical community to describe general aches and pains but myalgia refers exclusively to muscles whereas pain in joints, for example, is more correctly described as arthralgia and generalised pain affecting muscles, joints and fibrous connective tissues such as tendons may be termed fibromyalgia. The word myalgia is modern Latin but is derived from old Greek components “myo” = muscle, “alg” = pain and “ia” = a state or medical condition.

As almost every part of the human body has muscle tissue, it follows that myalgia can occur almost anywhere. It may affect a single muscle or muscle group or may be more widespread or even generalised. It is important to remember that myalgia is a symptom rather than a disease and any investigation should primarily focus on the determination of the underlying causes.



Symptoms of Myalgia

Myalgia is of course simply another way of saying “muscle pain” and so the symptoms of myalgia could be regarded as being self-explanatory but, in order to diagnose the condition, it is worth looking at some of the symptoms likely to be present.

  • Muscular pain present. This may be localised or widespread and the nature of the pain can differ from being an ache to a sharp stabbing pain.

  • The pain may be mild, moderate or severe and may last for a few minutes at a time or may be constant.

  • In addition to pain, the patient may also suffer with a fever, chills and feeling of general malaise indicating that an infection is likely.

  • The muscular pain may be accompanied by pain in the joints possibly indicating a further diagnosis such as fibromyalgia.

  • A feeling of extreme tiredness and fatigue may make normal everyday tasks very difficult.

  • Constant pain almost invariably leads to depression.

Myalgia Types

Although the word myalgia has a very broad definition, there are generally considered to be several main types of this condition these being:

  • Polymyalgia rheumatica

    – This is a chronic type of myalgia which usually only affects older patients with most being over the age of seventy at the time of diagnosis. In many ways, the symptoms are similar to rheumatoid arthritis with pain and stiffness which is usually at its worst in the morning. The shoulders, neck and hips are commonly affected and other symptoms include fever, fatigue, loss of appetite, sweating and depression.

  • Trapezius myalgia

    – As its name suggests, this form of myalgia refers to pain in and around the trapezius muscle. This can be the result of trauma such as in the case of a whiplash injury but can also be regarded as a work-related injury often arising from long periods of working in front of a computer screen.

  • Fibromyalgia

    – This is another chronic form of myalgia in which the muscles, joints and connective tissues are involved. Its causes are complex and believed to involve the central nervous system. It affects much of the body and some other symptoms include increased pain sensitivity, muscle stiffness and pain, fatigue, problems with memory and concentration, headaches, difficulty sleeping and depression.

  • Epidemic myalgia

    – The most common type of epidemic myalgia is Bornholm disease which is caused by a viral infection. Along with symptoms such as generalised muscle pain and fever, this type of myalgia particularly affects the intercostal muscles (between the ribs) causing an acute stabbing pain. This illness is fairly short-lived and usually clears up without treatment in about a week.

  • Traumatic myalgia

    – This is the most common type of myalgia caused by accident, injury or overexertion.

Myalgia Causes

Everyone has suffered some degree of myalgia at some time and, although the degree of severity may range from a dull ache to debilitating pain, it is seldom a serious health condition. The simplest type of myalgia is due to muscle overuse or injury and this is commonly encountered in many kinds of sports. Other forms of overexertion such as lifting heavy objects or overreaching, twisting or stretching are all common causes. Traumatic injury also often results in myalgia with sports injuries often leading to such pains. Other typical causes include road accidents with injuries such as “whiplash” commonly resulting in myalgia to the neck muscles. Compression, hyper-extension, strains and sprains all give rise to myalgia and crush injuries are potentially some of the most serious causes.

Apart from the easily understood physical causes of myalgia, the condition often occurs without any obvious external reason. In cases where a single muscle or localised group of muscles is affected, a physical cause is most likely but generalised muscle pain is more likely to have other causes such as being due to an infection. Many viral infections, including influenza and the common cold, give rise to myalgia and the symptoms normally disappear as the illness progresses and recedes. There are however some conditions giving rise to long-term myalgia including autoimmune disorders such as systemic lupus erythematosus. Multiple sclerosis also causes similar symptoms although in this case it is actually neurological pain perceived as muscular pain. Chronic fatigue syndrome, HIV and AIDS also include myalgia among their symptoms.

Parasitosis, or infection due to parasites, is another often overlooked possible cause of myalgia. There are many tropical diseases due to a parasitic vector but even in temperate climes there are risks from ticks and fleas as well as various parasitic worms.

Endocrine disorders also often give rise to a wide range of symptoms including myalgia. Conditions such as diabetes, Cushing’s disease, Addison’s disease, hyperthyroidism and hypothyroidism are some of the best known examples.

The use of various drugs is also associated with myalgia. Fibrates, statins, ACE inhibitors and some retro-viral drugs all list such pains among possible side effects and the withdrawal of certain drugs such as opiates and corticosteroids can also result in myalgia.

Other rare, but potentially serious causes of myalgia, include genetic disorders such as muscular dystrophy, some cancers, or infections from abscess within the tissue. Nutritional problems or potassium deficiency may also result in symptoms of this type.

Myalgia Treatments

As myalgia is a symptom rather than a disease, all forms of treatment need to be focussed on dealing with the underlying causes of the condition. In cases where there is a fairly obvious physical cause such as trauma or overuse, a regime of rest along with gentle exercise is usually effective and localised pain may be aided by the use of hot and/or cold compresses. Maintaining the mobility of the affected part generally speeds up the recovery process and gentle stretching and light exercise are recommended. The immobilisation of the affected muscles, such as using a head collar following a whiplash injury is not normally recommended and such restraints are usually reserved for cases where serious spinal injuries are present or suspected.

In all other cases, myalgia treatments should initially deal with the causative factor. Infections, especially viral, may simply have to run their course whereas others may respond to treatment with appropriate drugs. Where systemic abnormalities are suspected, tests will be performed including blood tests and treatment tailored to enable the stabilisation of the various factors. Once this has been achieved, the physical relief of the symptoms can continue along the lines above.

Myalgia and Myositis

For some reason, there is often some confusion between the terms myalgia and myositis. Both refer to the muscles, hence the “my” and “myo” prefixes, but whereas “-algia” means pain, “-itis” refers to inflammation. This may seem like a minor detail but the two conditions are usually completely unconnected. The determination of what actually constitutes inflammation in a medical sense was established many years ago and is usually summarised as: calor, dolor, rubor, tumor meaning: heat, pain, redness and swelling. The fifth descriptor, functio laesa, loss of function, was later added. From this it can be seen that myositis will invariably include muscle pain among its symptoms, myalgia on the other hand will always include pain and may also satisfy some of the other descriptors but will never meet the full five conditions required for a diagnosis of myosotis.

The symptoms of myosotis are also significantly different to those of myalgia and, in addition to its inflammatory nature, problems such as tripping, falling and extreme fatigue are usually present. As with myalgia, infections or medication can be the cause but this disease is often due to problems with the body’s immune system which attacks the muscle cells. Polymyositis primarily affects the muscles of the shoulders, hips and thighs and also affects the joints, lungs and heart with dermatomyositis also affecting the skin causing rashes. This type of myosotis tends to be of varying severity but generally gets worse over a period of years.

Myalgia by comparison is generally straightforward to treat. It is not regarded as a particularly serious or life-threatening condition. Most cases are simply part of normal everyday life and, with suitable treatment, a full recovery is usually to be expected.


Please enter your comment!
Please enter your name here