Pregnant women drink water all the time or feel thirsty may be physiological phenomenon, may also be gestational diabetes, hyperthyroidism and other diseases. 1. Physiological phenomenon: If a pregnant woman stays in a hot environment for a long time, the skin’s ability to dissipate heat decreases, leading to an increase in body temperature, which in turn causes dehydration, and the situation of drinking water all the time and still feeling thirsty is a normal physiological phenomenon, and there is no need to worry too much. 2. Gestational diabetes mellitus: the occurrence of this disease is associated with increased glucose demand, increased insulin resistance and relative insufficiency of insulin secretion, common risk factors are genetic history, maternal age ≥ 35 years, obesity, adverse maternal history. Some pregnant women may experience symptoms such as thirst, excessive drinking and urination, which can be manifested as the pregnant woman has been drinking water or still feeling thirsty, but the symptoms are relatively mild and easy to be ignored. 3. Hyperthyroidism: This disease occurs mainly because the placenta produces a large amount of human chorionic gonadotropin after pregnancy, which in turn promotes the overproduction of thyroid hormones by the thyroid gland, thus easily causing hyperthyroidism. When a pregnant woman has the symptom of feeling thirsty despite drinking water all the time, if physiological phenomena are ruled out, she needs to go to the hospital in time to consult a doctor to clarify the specific cause.