Headache and Muscle Ache: Causes

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Exploring the causes of headaches and muscle aches

Pain such as headaches and other muscle aches throughout the body arise from the body’s immune response to a viral infection.1

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The role of inflammation in headaches and muscle aches

An infection from an influenza virus triggers an immune response within the infected patient, resulting in the release of various chemotactic, proinflammatory, and immunoregulatory cytokines.1 The activity of these inflammatory mediators is responsible for triggering various symptoms typical of the flu, including body aches.2

  • The immune response

    Woman headache in bed

    The body’s immune response to infection

    Infection by an influenza virus triggers the body’s epithelial cells and leukocytes to release various cytokines to activate cells of the immune system. Each group of cytokines plays a role, such as:1

    • Upregulation of immune cell expression
    • Direction of leukocyte migration towards the infection site

    The presence of cytokines, as well as the release of prostaglandins from triggered cells, are thought to be the cause of the headaches and muscle pains experienced during the flu.2,3

  • Other Causes of Headaches

    Headaches may arise from causes other than the flu

    Many conditions and diseases list headache as a symptom; it is not exclusive to viral infections. A headache may be a sign of a life-threatening disease, or something as benign as caffeine withdrawal.4

    Woman watery red eyes

    Allergy headaches

    An allergy headache typically presents as a generalised headache along with other allergy symptoms, such as nasal congestion or watery eyes.4

    Hyper tension headache icon

    Hypertension headaches

    This may present as a generalised pain, or in the location of a “headband” across the head. It tends to be most severe in the mornings and lessens later in the day. Associated with malignant hypertension.4

    Tension headache

    Tension headaches

    A dull, non-throbbing pain on both sides of the head, associated with tightness around the scalp and neck. Tension headaches may arise from mental or emotional stress.4

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