Taking a bath with a fast beating heart may be caused by vasodilatation, or it may be caused by hypoglycemia, hypokalemia, and low blood pressure. 1. Vasodilatation: When patients take a bath, due to the high temperature, the skin blood vessels will expand, resulting in insufficient blood volume. At this time, the heart will accelerate the movement of blood supply, so the patient will appear in the bath heart beating fast heart difficult phenomenon, is a normal physiological phenomenon. 2. Hypoglycemia: the causes of hypoglycemia are numerous, mainly due to insufficient sugar intake, insufficient generation and other factors. The main symptoms of patients are anxiety, fatigue, shortness of breath, palpitations, etc., which will lead to the phenomenon of heart beating fast and feeling uncomfortable when taking a bath. 3. Hypokalemia: Hypokalemia is mainly caused by too little potassium intake, and patients will experience symptoms such as fatigue, tachycardia and muscle weakness. Hypokalemia will lead to symptoms such as polyuria, periodic paralysis, etc. Patients will also have mental depression and drowsiness. 4. Hypotension, myocardial infarction and other diseases can also lead to the phenomenon that the patient’s heart beats fast when taking a bath. When the patient has the symptom of heart beating fast in the bath, it may be a normal physiological phenomenon caused by the expansion of blood vessels, and does not need special treatment. If the disease is caused, the patient should consult a doctor in time, and follow the doctor’s instructions for treatment.