Generally speaking, hardness mainly refers to the hardness of the male penis after erection, and the hardness of four grades belongs to the normal standard. The hardness of the male penis after erection can be mainly divided into four levels: 1. Grade 1 indicates that there is some response after receiving stimulation, but the hardness is insufficient and as soft as tofu, which belongs to severe impotence. 2. Grade 2 means that there is a response after stimulation, but it is not possible to have sex, as soft as a banana, which belongs to the middle degree of impotence. 3. Grade 3 means that the response to stimulation is strong, barely able to have sex, but the erection is not good, which is mild impotence, and the hardness is about the same as a banana with skin. 4. Grade 4 means that the response to stimulation is strong, and the patient can have sex perfectly, with a normal erection and a hardness like that of a cucumber. When the patient has a lack of erection hardness, can be improved through regular work and rest, healthy diet, avoid sedentary and other methods, if necessary, can go to the regular hospital for consultation.