"Erectile dysfunction can be a very serious issue because it's a marker of underlying cardiovascular disease, and it often occurs before heart conditions become apparent. Therefore, men should consider improving their weight and overall nutrition, exercise more, drink less alcohol and have a better night's sleep, as well as address risk factors such as diabetes, high blood pressure and cholesterol.
Erectile dysfunction can occur as a side effect of medication taken for another health condition. Common culprits are high blood pressure meds, antidepressants, some diuretics, beta-blockers, heart medication, cholesterol meds, antipsychotic drugs, hormone drugs, corticosteroids, chemotherapy, and medication for male pattern baldness, among others.
The recommended starting dose of tadalafil for use as needed for most patients is 10 mg taken orally approximately one hour before sexual activity. A doctor may adjust the dose higher to 20 mg or lower to 5 mg depending on efficacy and side effects. Doctors recommended that patients take tadalafil no more frequently than once per day. Some patients can take tadalafil less frequently since the improvement in erectile function may last 36 hours. Patients may take tadalafil with or without food. Tadalafil is currently the only PDE5 inhibitor that is FDA-approved for daily use for erectile dysfunction and is available in 2.5 mg or 5 mg dosages for daily use.
Aging, liver and kidney problems, and concurrent use of certain medications (such as erythromycin [an antibiotic] and protease inhibitors for HIV) slows the metabolism (breakdown) of sildenafil. Slowed breakdown allows sildenafil to accumulate in the body and potentially may increase the risk of side effects. Therefore, in men over 65 years of age, in men with significant kidney and liver disease, and in men who also are taking medications called protease inhibitors, the doctor will initiate sildenafil at a lower dose (25 mg) to avoid accumulation of sildenafil in the body. A protease inhibitor ritonavir (Norvir) is especially potent in increasing the accumulation of sildenafil, thus men who are taking Norvir should not take sildenafil doses higher than 25 mg and at a frequency of no greater than once in 48 hours. Other medications that may affect the level of sildenafil include erythromycin and ketoconazole.
Another study compared the response of surgically and medically castrated rabbits to vardenafil with that of control rabbits.  Castrated rabbits did not respond to vardenafil, whereas noncastrated rabbits did respond appropriately. This result suggests that a minimum amount of testosterone is necessary for PDE5 inhibitors to produce an erection.
Additionally, the physiologic processes involving erections begin at the genetic level. Certain genes become activated at critical times to produce proteins vital to sustaining this pathway. Some researchers have focused on identifying particular genes that place men at risk for ED. At present, these studies are limited to animal models, and little success has been reported to date.  Nevertheless, this research has given rise to many new treatment targets and a better understanding of the entire process.
If you’re experiencing psychological ED, you may benefit from talk therapy. Therapy can help you manage your mental health. You’ll likely work with your therapist over several sessions, and your therapist will address things like major stress or anxiety factors, feelings around sex, or subconscious conflicts that could be affecting your sexual well-being.
Penis pumps produce erections by drawing blood, via air suction, into the penis. The devices consist of a cylindrical tube, 12 to 18 inches long, connected by a small air hose to a hand pump (on many models this resembles the squeeze mechanism on a blood pressure monitor). Users place the tube over the penis then pump to produce an erection. They must then place an elastic band around the base of the penis to keep the blood there and maintain the erection.
Replacement testosterone is available as oral pills, intramuscular injections, skin patches, and a gel that is rubbed into the skin. Men with low sexual desire and ED may have low testosterone (male hormone) levels. Hormone replacement may occasionally be of some benefit, especially when used in combination with other therapies. Testosterone supplementation alone is not particularly effective in treating erectile dysfunction. Sexual desire and an overall sense of well-being are likely to improve when serum testosterone levels (the levels in the blood) are restored. This can take several months after starting testosterone replacement.
3. Are there physical causes of erectile dysfunction? Erectile dysfunction may be a symptom of underlying medical conditions, which if not detected may cause further medical problems. A prior history of cigarette smoking, heart attacks, strokes, and poor circulation in the extremities (for example, intermittent claudication or cramping in your leg[s] when you walk) suggest atherosclerosis as the cause of the erectile dysfunction. Loss of sexual desire and drive, lack of sexual fantasies, gynecomastia (enlargement of breasts), and diminished facial hair suggest low testosterone levels. A prior history of pelvic surgery or radiation and trauma to the penis/pelvis/perineum can cause problems with the nerves and blood vessels. Symptoms of intermittent claudication of the lower extremities with exercise may suggest a vascular problem as a cause of the erectile dysfunction.
The availability of phosphodiesterase-5 (PDE5) inhibitors—sildenafil, vardenafil, tadalafil, and avanafil—has fundamentally altered the medical management of ED. In addition, direct-to-consumer marketing of these agents over the last 15 years has increased the general public’s awareness of ED as a medical condition with underlying causes and effective treatments.
There have been some studies to suggest that a placebo effect that improves ED may work for some men. One study found that men taking an oral placebo pill showed as much improvement in ED symptoms as men who took actual medication to improve ED. Conversely, men who were given therapeutic suggestions to improve ED did not see signs of symptom improvement.
Tadalafil shares the common side effects of the PDE5 inhibitors, however, due to its effect on PDE11, another phosphodiesterase located in muscle, tadalafil has been associated with muscle aches. Back pain and muscle aches occur in less than 7% of men taking tadalafil and in most patients will go away without treatment within 48 hours. When treatment was necessary, acetaminophen (Tylenol) and nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Motrin, Advil) or naproxen (Aleve) were effective. Rarely do the muscle aches and back pain cause men to stop using tadalafil.
Associated morbidity may include various other male sexual dysfunctions, such as premature (early) ejaculation and male hypoactive sexual desire disorder. The NHSLS found that 28.5% of men aged 18-59 years reported premature ejaculation, and 15.8% lacked sexual interest during the past year. An additional 17% reported anxiety about sexual performance, and 8.1% had a lack of pleasure in sex. 
In comparison, 37% of men who had received external radiotherapy as their primary therapy reported the ability to attain functional erections suitable for intercourse, along with 43% of men who had received brachytherapy as primary treatment. Pretreatment sexual health-related quality of life score, age, serum prostate-specific antigen (PSA) level, race or ethnicity, body mass index, and intended treatment details were associated with functional erections 2 years after treatment. 
The inability to achieve or sustain a sufficiently firm penile erection (tumescence) to allow normal vaginal sexual intercourse. The great majority of cases are not caused by organic disease and most men experience occasional periods of impotence. It is often related to anxiety about performance and is usually readily corrected by simple counselling methods which prescribe sensual massage but forbid coitus. Organic impotence may be caused by DIABETES, MULTIPLE SCLEROSIS, spinal cord disorders and heart disease. Many cases can be helped by the drug SILDENAFIL (Viagra).
What are the alternatives to viagra? Erectile dysfunction, when a man cannot achieve or maintain an erection, is a common condition that causes much distress. Viagra is just one of several drug treatments that can help relieve the problem. Other methods and treatments can help, too, including alternative herbal remedies that people may wish to try. Read now
Factors that mediate contraction in the penis include noradrenaline, endothelin-1, neuropeptide Y, prostanoids, angiotensin II, and others not yet identified. Factors that mediate relaxation include acetylcholine, nitric oxide (NO), vasoactive intestinal polypeptide, pituitary adenylyl cyclase–activating peptide, calcitonin gene–related peptide, adrenomedullin, adenosine triphosphate, and adenosine prostanoids.
Quitting smoking, exercising regularly, losing excess weight, curtailing excessive alcohol consumption, controlling hypertension, and optimizing blood glucose levels in patients with diabetes are not only important for maintaining good health but also may improve or even prevent progression of erectile dysfunction. It is unclear if such lifestyle changes can reverse erectile dysfunction. However, lifestyle improvements may prevent progression of the erectile dysfunction. Some studies suggest that men who have made lifestyle improvements experience increased rates of success with oral medications.
The nerves and endothelium of sinusoids and vessels in the penis produce and release transmitters and modulators that control the contractile state of corporal smooth muscles. Although the membrane receptors play an important role, downstream signaling pathways are also important. The RhoA–Rho kinase pathway is involved in the regulation of cavernosal smooth muscle contraction. 
Picture of penile tumescence monitor. This penile tumescence monitor is placed at the base and near the corona of the penis. It is connected to a monitor that records a continuous graph depicting the force and duration of erections that occur during sleep. The monitor is strapped to the leg. The nocturnal penile tumescence (NPT) test is conducted on several nights to obtain an accurate indication of erections that normally occur during the alpha phase of sleep.
The Massachusetts Male Aging Study (MMAS) documented an inverse correlation between ED risk and high-density lipoprotein (HDL) cholesterol levels but did not identify any effect from elevated total cholesterol levels.  Another study involving male subjects aged 45-54 years found a correlation with abnormal HDL cholesterol levels but also found a correlation with elevated total cholesterol levels. The MMAS included a preponderance of older men.
Ginseng, specifically “red ginseng,” is known as the “herbal Viagra” that helps puts to rest men’s bedroom woes. Red ginseng is when the root has been steamed and then dried. The ginseng root is the part of the plant that is mostly used as a natural remedy when in its supplement form. However, the plant must be grown for a minimum of five years before it can be used. In a 2008 review, seven studies on red ginseng and ED, ranging in dosages from 600 to 1,000 milligrams three times a day, were found to provide evidence for the effectiveness of the herb in ED treatment.
A vacuum erection device is a plastic tube that slips over the penis, making a seal with the skin of the body. A pump at the other end of the tube makes a low-pressure vacuum around the erectile tissue, which results in an erection. An elastic ring is then slipped onto the base of the penis. This holds the blood in the penis (and keeps it hard) for up to 30 minutes. With proper training, 75 out of 100 men can get a working erection using a vacuum erection device.