Erectile Dysfunction Causes

The greatest medical risk factors for erectile dysfunction include diabetes mellitus, heart disease, hypertension and having a decreased high-density lipoprotein level. Men who have undergone radiation therapy and surgery for prostate or bladder cancer are also at a higher risk for developing the condition.

In addition, the following factors, either alone or in combination, may also cause erectile dysfunction:

• Psychological causes, such as performance anxiety, a strained relationship, lack of sexual arousability and mental health disorders, including depression and schizophrenia.
• Neurological disorders, including Parkinson's disease, Alzheimer's disease, stroke and brain trauma. These conditions often cause erectile dysfunction by decreasing libido or preventing the initiation of an erection.
• Hormonal disorders, such as hyperprolactinemia and androgen deficiency, which can decrease nocturnal erections and libido.
• Vascular conditions and factors, including heart disease, hypertension, hyperlipidemia, cigarette smoking, diabetes mellitus and pelvic irradiation. A disorder called, veno-occlusive dysfunction, in which the veins are unable to close during an erection, also can cause erectile dysfunction.
• Certain medical drugs, such as antipsychotic, antidepressant and centrally acting antihypertensive drugs, may disturb the pathways involved in sexual function. Other drugs known to cause erectile dysfunction include Cimetidine, a histamine H2-receptor antagonist, estrogens and drugs with antiandrogenic action, such as ketoconazole and cyproterone acetate.
  
  Smoking cigarettes and drinking large amounts of alcohol, as well as suffering from chronic alcoholism, also can cause erectile dysfunction.
• Other factors, such as old age and chronic renal failure, can also contribute to erectile dysfunction.