Cialis (tadalafil) is a potent medication used to treat erectile dysfunction. Although it is not likely to cure the condition, a single dose of Cialis will provide for a stable erection each time you take it. Your age can be of importance when your dose is being determined. People older than 65 are expected to be more sensitive to the effects of Cialis and therefore need a lower dose of this medicine. The following medical conditions are also supposed to be reported to your doctor in advance for your dose to be accurate and safe: bleeding disorder, a history of a heart attack, liver disease, chest pain, kidney disease, heart disease, retinitis pigmentosa, high or low blood pressure, a recent history of a stroke, blood cell disorder, physical deformity of the penis, congestive heart failure, or stomach ulcer. Some of these conditions may even require additional tests that will help to establish the safety of using Cialis. Never take Cialis if you have recently used nitrate-based drugs, certain alpha-blocker medications, nitroprusside, or recreational drugs, as a dangerous drop in blood pressure is possible. A drop in blood pressure can lead to a number of serious complications, such as stroke, heart attack and sometimes even death. You may be recommended to take from 25 to 100 mg of Cialis and taking the exact dose recommended is the only way to benefit from your treatment. The following symptoms are possible in case of an overdose: nausea, light-headedness, fainting, chest pain, and irregular heartbeat. You will need to seek emergency medical help if an overdose of Cialis is suspected. Loss of hearing, dizziness, hives, blurred vision, ringing in ears, changes in color vision, rash, erection that lasts longer than 4 hours, and chest pain are rare but serious reactions you may have as a result of using Cialis. They need to be reported to your health care provider as soon as possible to prevent them from getting worse. Less serious side effects are possible and occur in 15% of patients using Cialis. The following ones are considered to be mild side effects: back pain, stuffy nose, memory problems, headache, warmth or redness in your face, neck, or chest, diarrhea, sore throat, upset stomach, and muscle pain. If any of the mild side effects mentioned change in intensity and start to bother you too much - report them to your health care provider as soon as possible.