Blood serum concentrations are much lowerâonly about 0.4% of the body's potassium is found in blood serum. As noted above, hypokalemia can be caused by the sudden uptake of potassium ions from the bloodstream by muscle or other organs or by an overall depletion of the body's potassium.
Early symptoms of the flu may include conditions such as excessive or sudden fatigue or body aches and chills, according to Healthline. While fatigue can be an early symptom of a cold, in people who have the flu, the fatigue is much worse.
A bout of the flu typically lasts one to two weeks, with severe symptoms subsiding in two to three days. Flu symptoms usually start within one to four days after infection, and they may come on suddenly. The first sign of influenza is often a fever or chills, followed by headache, sore throat, dry cough, runny nose, muscle aches, and fatigue. As the illness progresses, a person may have warm, flushed skin, watery or bloodshot eyes, a severe cough that brings up phlegm, nasal congestion, and nausea and vomiting.