There is no specific standard for how old a man is when his sexual ability begins to decline, for example, normal men may gradually decline after the age of 45, and it is difficult to judge the age of a patient who suffers from an underlying disease. A man’s sexual ability is usually related to hormone levels, when a man is about 45 years old, androgen levels will gradually decline, and androgen is the main influence on male sexual fantasies, sexual activities, etc., so when normal male androgen levels decline, sexual ability will also begin to decline. When overworked, the hormone level may be abnormal around the age of 40, leading to the beginning of the decline in sexual ability. If a man suffers from some diseases, such as hypertension, high blood pressure, high blood fat, diabetes, etc., due to this part of the patient’s psychological pressure and side effects of drugs, etc., can lead to a decline in the patient’s sexual function, and these diseases are often preferred in the 40 years of age, so men suffering from these underlying diseases may begin to decline in sexual function at around 40 years of age. Decline in sexual ability is related to many factors and varies from person to person. It is recommended that patients pay attention to rest, avoid overwork, and if the decline in sexual ability occurs, they should consult a doctor in a timely manner to clarify the cause of the disease and under the guidance of the doctor for treatment.