Yangqiang is also known as strong middle, and its symptoms mainly include persistent erection of the penis, which remains erect for several hours or days and is painful to touch, or is accompanied by a continuous flow of semen. Patients with yangqiang can be clinically classified into two types of evidence: yin deficiency fire and liver damp heat. Patients with liver damp heat have symptoms such as penile swelling and pain, blood stasis, bruising, painful urination and difficulty in urination, as well as symptoms such as bitterness and thirst, constipation and yellow tongue coating. Patients with yin deficiency fire have symptoms of yin deficiency fire such as red tongue with little coating, dry mouth, irritable heat in the five hearts, hot flashes and night sweats, constipation, thin and weak pulse. The state of yang strength is usually not dependent on the effects of sexual arousal. Its cause is sometimes more difficult to determine, and the most common causes are sickle cell anemia, erythrocytosis and leukemia, which cause changes in hemodynamics in the microvasculature due to changes in certain components of the patient’s blood, resulting in blood stasis, which causes the inability to recover from an erection. It is also seen in cases such as diabetes, neurological infections, tumors, lumbosacral trauma and taking certain medications. Once the symptoms of yangqiang appear, you should seek medical attention in time. Improper treatment or delayed treatment is likely to develop from abnormal penile erection to penile inability to erect, evolving into permanent impotence and infertility.