Muscle Pain: Clinical Meaning

Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that causes inflammation in the joints, leading to pain, swelling, and eventual joint damage. Unlike osteoarthritis, RA is systemic and can affect organs including the heart and lungs.

Anxiety Disorder

Anxiety disorders are among the most common mental health conditions, characterized by excessive fear, worry, or nervousness that interferes with daily activities. Types include generalized anxiety disorder (GAD), panic disorder, and social anxiety.

Parkinson's Disease

Parkinson's disease is a progressive neurological disorder affecting movement, caused by the loss of dopamine-producing neurons. Symptoms include tremor, rigidity, slowness of movement, and balance problems. There is no cure, but treatments can manage symptoms.

Influenza (Flu)

Influenza is a highly contagious respiratory viral illness caused by influenza A or B viruses. It spreads through respiratory droplets and causes sudden fever, severe body aches, fatigue, cough, and headache. Annual vaccination is recommended for prevention.

COVID-19

COVID-19 is an infectious respiratory disease caused by the SARS-CoV-2 virus. Symptoms range from mild (fever, cough, fatigue) to severe (pneumonia, respiratory failure). Long COVID affects some patients with persistent symptoms lasting months.

Pericarditis

Pericarditis is inflammation of the pericardium (the sac surrounding the heart), causing sharp, pleuritic chest pain that improves when leaning forward. Viral infections are the most common cause; NSAIDs are the primary treatment.

Dengue Fever

Dengue fever is a mosquito-borne viral infection causing high fever, severe headache, muscle and joint pain, and a characteristic skin rash. Dengue hemorrhagic fever is a severe form with bleeding and organ impairment.

Hepatitis C

Hepatitis C is a blood-borne viral infection causing chronic liver inflammation that can progress to cirrhosis and liver cancer over decades. Direct-acting antiviral therapy achieves cure rates above 95%.

Lyme Disease

Lyme disease is a tick-borne bacterial infection caused by Borrelia burgdorferi, presenting with a bull's-eye rash (erythema migrans), flu-like symptoms, and if untreated, joint, neurological, and cardiac complications.

Infectious Mononucleosis (Mono)

Infectious mononucleosis, caused by Epstein-Barr virus, presents with severe fatigue, sore throat, swollen lymph nodes, and splenomegaly. It primarily affects adolescents and young adults; strenuous activity must be avoided due to spleen rupture risk.

Toxoplasmosis

Toxoplasmosis is caused by the parasite Toxoplasma gondii, transmitted through cat feces, undercooked meat, or vertically to the fetus. It is usually asymptomatic in healthy individuals but can cause severe disease in immunocompromised patients and congenital infection.

Polymyositis

Polymyositis is an inflammatory myopathy causing progressive proximal muscle weakness, elevated muscle enzymes, and abnormal electromyography. Unlike dermatomyositis, it lacks the characteristic skin findings; treatment includes corticosteroids and immunosuppressants.

Fibromyalgia

Fibromyalgia is a chronic condition causing widespread musculoskeletal pain, fatigue, sleep disturbance, and cognitive difficulties ("fibro fog"). Central sensitization is the underlying mechanism; multimodal treatment includes exercise, cognitive behavioral therapy, and medications.

Bursitis

Bursitis is inflammation of a bursa (fluid-filled sac cushioning bones and tendons), causing localized pain and swelling near joints. The shoulder, hip, elbow, and knee are commonly affected; rest, ice, and NSAIDs are initial treatments.

Tendinitis

Tendinitis is inflammation of a tendon, most commonly affecting the shoulder (rotator cuff), elbow (tennis/golfer's elbow), Achilles tendon, and patellar tendon. It causes localized pain worsening with activity; eccentric exercises and load management are key treatments.

Scoliosis

Scoliosis is an abnormal lateral curvature of the spine, most commonly idiopathic and developing during adolescence. Mild curves are observed; progressive curves require bracing or surgical correction to prevent cardiopulmonary compromise.

Chronic Fatigue Syndrome (ME/CFS)

Myalgic encephalomyelitis/chronic fatigue syndrome is a complex, debilitating condition causing profound fatigue not improved by rest, post-exertional malaise, cognitive difficulties, and sleep disturbances lasting over 6 months. No curative treatment exists; management focuses on symptom relief and pacing.

Long COVID (Post-COVID Syndrome)

Long COVID refers to persistent symptoms lasting more than 12 weeks after acute COVID-19 infection, including fatigue, brain fog, breathlessness, and chest pain. Post-exertional malaise and autonomic dysfunction are prominent features; management is multimodal and symptom-based.

Trichinellosis

Trichinellosis is caused by Trichinella spiralis larvae encysted in muscle tissue, typically acquired from eating undercooked pork or wild game. It presents with fever, periorbital oedema, and severe myalgia. Treatment includes mebendazole and corticosteroids.

Food Poisoning

Food poisoning is an illness caused by consuming contaminated food or water. Symptoms typically begin within hours to days of exposure and range from mild discomfort to severe dehydration.

Burnout Syndrome

Burnout is a state of chronic stress leading to physical and emotional exhaustion, cynicism, and feelings of ineffectiveness. The WHO recognizes it as an occupational phenomenon.

Vitamin C Deficiency (Scurvy)

Vitamin C deficiency in its severe form causes scurvy. Subclinical deficiency affecting immune function and wound healing is more common in developed countries.

Salmonella Infection

Salmonellosis is a common bacterial food poisoning caused by Salmonella bacteria. It typically causes diarrhea, fever, and stomach cramps beginning 12-72 hours after infection.

Myocarditis

Myocarditis is inflammation of the heart muscle, most commonly caused by viral infections. It can affect the heart's electrical system and pumping ability, ranging from mild to life-threatening.