Why does a cold cause aching limbs?

Introduction

Pain in the limbs is a symptom accompanying a cold. They occur acutely with the onset of a cold and usually subside with the remaining symptoms within a few days. The arms and legs are primarily affected.

The intensity and distribution of the pain is variable and depends on the severity of the cold. Reasons for the occurrence of pain in the limbs are, on the one hand, the complex defence reaction of the body, as well as a loss of electrolytes due to the development of fever. With simple measures a good relief of the pain in the limbs can be achieved.

What is limb pain?

Pain in the limbs is pain of varying intensity in the arms or legs. It can be muscle pain, but also an increased sensitivity of the skin to pain. The pain can occur at any height of the limbs, i.e. on the shoulder, fingers, hips and feet.

The pain does not necessarily affect all limbs equally. Pain can also occur only on the legs or only on the arms and also here in varying degrees. The intensity of the pain can vary from a barely perceptible sensation to severe pain when resting and moving. The character of the pain is often described as pulling or biting.

Why does a cold cause aching limbs?

Pain in the limbs is caused by the body’s complex defense reaction against the pathogen. In most cases, the pathogens are viruses. If they are detected by the body, a cascade of different signal chains is triggered to activate the immune system.

In the process, many messenger substances are also released and an inflammatory reaction is produced in response to the pathogen. In most colds, this is mainly limited to the nasal region. To a certain extent, a weakened inflammatory reaction is also triggered in the rest of the body, as the messenger substances in the bloodstream circulate throughout the entire body.

In the course of this inflammatory reaction the pain threshold of the body is lowered. This means that the pain receptors in the skin and muscles respond more sensitively to stimuli with a feeling of pain. Thus, pain in the limbs can occur even though the focus of the inflammation is located in a different area.

Another mechanism leading to limb pain is triggered by an increase in body temperature. As part of the defence against pathogens, the pituitary gland increases the body’s target temperature. This increase in body temperature, which is perceived as the symptom fever, has a positive effect on the defense reaction.

As a side effect, however, the body loses fluid and important electrolytes such as sodium and potassium. These electrolytes are important for the contraction of muscles and in healthy people, reduced potassium levels are associated with extensive muscle strain. If the potassium content is reduced by fever alone, the same signal as during muscle exertion is still sent to the brain and a feeling of muscular limb pain occurs.