Hello, the side effects of Viagra are as follows: First, if the erection fails, it can damage the pudendal muscle tissue and even aggravate impotence. If the erection exceeds 4 hours, you must seek medical advice immediately; Dizziness: In clinical trials, it was found that 10 patients had 1? One suffers from severe headache, and the greater the dose, the more severe the headache; 3. Dizziness: About 3% of the drug users may have transient blurred vision. Some will also have the illusion of seeing blue light; 4. Dizziness: This drug may cause a sudden drop in blood pressure. If you take nitroglycerin and other drugs at the same time, you will immediately have dizziness or even fainting symptoms; V.? Cardiovascular disease: impotence may be a precursor of heart disease, diabetes or cancer, and taking this medicine may cover up the real condition; Sixth, permanent impotence: because Viagra is an exogenous drug, long-term use can produce drug dependence and form permanent impotence; 7. Glaucoma: Hong Kong ophthalmologists warned that taking Viagra can lead to a drop in blood pressure, but the blood pressure of glaucoma patients is higher, so that 3%-5% of people may have acute glaucoma, which can make people blind overnight, and even if cured, they cannot restore their original vision. Combined with the above seven side effects, it is recommended not to take it. If you really want to use it, use it once in a while, and don't be greedy even if there is no response.