Both ED and low testosterone (hypogonadism) increase with age. The incidence of the latter is 40% in men aged 45 years and older.  Testosterone is known to be important in mood, cognition, vitality, bone health, and muscle and fat composition. It also plays a key role in sexual dysfunction (eg, low libido, poor erection quality, ejaculatory or orgasmic dysfunction, reduced spontaneous erections, or reduced sexual activity). 
In other cases, men who habitually use alcohol or other drugs may experience similar results. Alcohol is a depressant to the central nervous system. This means that a little bit might be able to lighten the mood, but too much can basically shut down all communication between the brain and the penis. When this happens, no amount of will or stimulation will result in an erection. Other drugs can also affect the body’s ability to achieve an erection, including heroin and MDMA, otherwise known as ecstasy.
All these treatments listed above do not provide immediate effect on your body. If you need an instant erection, you should take a look at the topical erection treatment. Targeted delivery has been recently identified as an emerging alternative to orally administered products mainly due to the current concerns of the side effects that may occur from taking prescription drugs. Topical erection treatment presents a preferable delivery method to get an erection that enhances the desired effect directly to the intended site of action while limiting the exposure of the rest of the body to the ingredients.
Did you know that erectile dysfunction precedes coronary artery disease in almost 70 percent of cases.2 The arteries in the penis are smaller than those that cause heart disease symptoms, which means they are likely to be affected by blockages sooner. When the arteries in the penis are blocked, keeping an erection will be difficult regardless of your level of arousal.
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. 
Normal Male Sexual Ageing is ignored by health care professionals. There is never a clear discussion. The best that happens is that when it happens, instead of Male Sexual Decline being a known factor that should be quantified for each individual male by regular testing and awareness, the health care professional says, "Oh. This is normal.You can do other things and still keep sex enjoyable".
One thing you need to know. When you are experiencing anxiety, you get a stress response. You can read more about this here. A stress response is what you automatically feel, say, if a fight broke out near you. Your body gets ready to protect itself. During a stress response, blood is diverted away from less important areas to help your heart beat faster.
Drugs for treating impotence can be taken orally or injected directly into the penis or inserted into the urethra at the tip of the penis. Oral testosterone can reduce impotence in some men with low levels of natural testosterone. Patients also have claimed effectiveness of other oral drugs--including yohimbine hydrochloride, dopamine and serotonin agonists, and trazodone--but no scientific studies have proved the effectiveness of these drugs in relieving impotence. Some observed improvements following their use may be examples of the placebo effect, that is, a change that results simply from the patient's believing that an improvement will occur.
ED usually has something physical behind it, particularly in older men. But psychological factors can be a factor in many cases of ED. Experts say stress, depression, poor self-esteem, and performance anxiety can short-circuit the process that leads to an erection. These factors can also make the problem worse in men whose ED stems from something physical.