What causes fever and thigh pain?

Generally speaking, fever refers to an elevated body temperature. Leg pain during fever may be caused by factors such as skeletal muscle contraction, excessive lactic acid production, inflammatory factor stimulation, connective tissue diseases, or acute infectious diseases. Patients are advised to follow medical advice for symptomatic treatment. Specific analyses are as follows:

1. Skeletal Muscle Contraction

After the onset of fever, the body's thermoregulatory set point rises. During the rising phase of body temperature, heat production increases while heat dissipation decreases, leading to contraction and spasm of skeletal muscles throughout the body. In some individuals, the leg muscles may contract intensely, causing soreness or pain in the legs. Patients may take medications as prescribed by a doctor, such as carbamazepine tablets or clonazepam tablets.

2. Excessive Lactic Acid Production

During fever, the body’s metabolic rate increases, resulting in extensive glucose anaerobic glycolysis and lactic acid production. Accumulation of lactic acid in leg muscles can lead to leg pain. Drinking more water may help accelerate metabolism and promote the excretion of lactic acid through urine, providing supportive relief.

3. Inflammatory Factor Stimulation

Fever activates the body's immune system, often triggering the release of large amounts of inflammatory substances such as leukotrienes and interleukins. These substances may enter joint cavities and stimulate synovial tissues, potentially causing leg pain. As directed by a physician, patients may take antibiotics such as amoxicillin capsules or cefaclor sustained-release tablets to alleviate symptoms.

4. Connective Tissue Diseases

For example, rheumatic fever may be triggered by acute hemolytic streptococcal infection. During acute episodes, symptoms such as redness, swelling, heat, pain, and limited mobility in joints may occur. When affecting leg joints, it can cause leg pain accompanied by fever. Treatment involves using antibiotics to eliminate residual streptococcal infection. Medications such as dicloxacillin sodium tablets or erythromycin ethylsuccinate tablets may be used under medical guidance.

5. Acute Infectious Diseases

Conditions such as influenza or acute tonsillitis can cause significant high fever, which may lead to symptoms including headache, limb soreness, and general weakness. The fever-induced overproduction of lactic acid can accumulate in leg muscles, resulting in leg pain. In such cases, oral medications like cefadroxil capsules or ibuprofen tablets may be taken under medical supervision. With proper treatment, both fever and leg pain can be significantly relieved.

In addition, leg pain during fever may also be associated with leg tissue injury, soft tissue inflammation, osteomyelitis, bone tumors, or other conditions. It is advisable to seek timely medical evaluation to identify the underlying cause and receive targeted treatment under a doctor’s guidance.