Can blood be drawn for physical examination during menstruation?

Blood tests can generally be performed during menstruation, but some examination items may be affected by the menstrual cycle. fluctuations in hormone levels during menstruation may interfere with specific test results such as six sex hormones and thyroid function, but basic items such as blood routine and liver function are usually not affected. Most blood tests conducted during menstruation will not cause harm to physical health. Blood tests mainly collect venous blood. Menstrual bleeding is a physiological bleeding caused by endometrial shedding, and the two do not interfere with each other. The hemoglobin test in the blood routine may show slight fluctuations due to menstrual bleeding, but it is still within the normal physiological range. The results of tests for coagulation function, electrolytes, tumor markers, etc. are usually not affected by the menstrual cycle. If abnormal indicators need to be rechecked, it is recommended to avoid menstruation to eliminate interfering factors.

Special attention should be paid to the timing of the menstrual cycle in sex hormone related examinations. For example, reproductive hormones such as follicle stimulating hormone and luteinizing hormone show significant differences at different stages of menstruation, and clinical practice often requires baseline levels to be measured from the 2nd to the 5th day of menstruation. Although thyroid function tests are not directly affected by menstruation, some women may experience physiological elevation of thyroid stimulating hormone during menstruation. Iron protein testing may result in low values due to menstrual blood loss, and anemia screening suggests re examination after menstruation. Before the physical examination, the purpose of the examination should be fully communicated with the doctor. When planning pregnancy related examinations or endocrine evaluations, doctors will adjust the blood draw time according to the menstrual cycle. If there are no special requirements for regular health check ups, drawing blood during menstruation does not affect the clinical judgment of most tests. Pressing the puncture point for 5 minutes after blood draw can prevent bruising, and those with normal coagulation function during menstruation will not have an increased risk of bleeding. If there is an abnormal increase in menstrual flow or anemia symptoms in the near future, non emergency blood tests can be postponed.