Extreme fatigue and muscle aches

Influenza and COVID-19 may cause sudden whole-body aches, tiredness, fever, cough, or sore throat. Dengue fever and malaria need consideration after relevant travel or mosquito exposure, especially with fever, chills, headache, or marked weakness. Brucellosis can follow contact with infected animals or unpasteurised products. Hypothyroidism may cause gradually increasing tiredness, muscle discomfort, constipation, feeling cold, or dry skin. Fibromyalgia often involves widespread pain and unrefreshing sleep. Long COVID may leave fatigue and exertion-related worsening after an earlier infection.

Rest, drink fluids, and choose gentle movement only if it feels comfortable. Check your temperature and write down recent travel, insect bites, animal contact, food exposures, new medicines, and when symptoms started. Avoid strenuous exercise while acutely unwell. Arrange a clinical assessment if symptoms are intense, unexplained, recurring, or interfering with walking, work, or sleep.

Seek urgent care for breathing difficulty, chest pain, confusion, fainting, a severe headache, a stiff neck, unusual bleeding, very dark urine, or inability to keep fluids down. Fever after travel to a malaria-risk area deserves prompt medical assessment, even if other symptoms seem mild.

Could this be an infection or a thyroid problem? Do my travel or exposure history change the tests needed? How should I pace activity while recovering?