Blood vessel disorders

Blockage of arteries (peripheral vascular disease)

Claudication (painful, aching, cramping, or tired feeling in the muscles of the legs that occurs regularly and predictably during physical activity but is relieved promptly by rest)

Usually risk factors (for example, high blood pressure, diabetes, or abnormal blood levels of cholesterol and lipids)

Comparison of blood pressures measured in the ankle and arm at the same time (called the ankle-brachial index)

Testing for risk factors (for example, elevated blood glucose [sugar] and blood lipid levels)

Ultrasonographic measurement of blood flow in the arteries of the penis

Venous leak (when the veins in the penis cannot prevent blood from leaving the penis during an erection, as they normally do)

Erections that occur but cannot be sustained

Ultrasonographic testing of the arteries of the penis

Nerve disorders

Nerve damage caused by diabetes (diabetic neuropathy)

Known diabetes

Sometimes numbness, burning, or other pains of the feet

Sometimes urinary incontinence

A doctor's examination

Sometimes electromyography and nerve conduction studies

Multiple sclerosis

Intermittent episodes of weakness or numbness in different parts of the body at different times

MRI

Sometimes spinal tap (lumbar puncture) and tests of spinal fluid

Nerve injury during pelvic surgery or radiation therapy

Known surgery (such as radical prostatectomy) or radiation therapy

Only a doctor's examination

Spinal cord disorders (such as tumors or injuries)

Numbness in the area between the penis and anus

Usually other symptoms of spinal cord disorder (for example, numbness and weakness of legs and incontinence)

MRI

Prolonged pressure in the buttocks and genital area (the so-called saddle area), as occurs when riding a bicycle or a horse

Usually competitive athletes who bicycle for long periods

Symptoms occur shortly after riding

Only a doctor's examination

Prostatitis (inflammation of the prostate)

Pain in the pelvic or groin area and bothersome urinary symptoms, such as pain, a burning sensation, blood in the urine, having to urinate frequently, or having difficulty starting to urinate

Urine testing

Stroke

Known stroke

Only a doctor's examination

Hormonal disorders

Hypogonadism (testosterone deficiency)

Loss of sex drive, sleep disturbances, and depression or mood changes

Eventually, decreases in the size of muscles and testes, bone density, and body hair

Eventually, an increase in body fat and breast size

Measurement of the testosterone level in the blood

Cushing syndrome

Round face, increased body fat in the trunk, purple streaks on the abdomen, high blood pressure, and mood changes

Measurement of levels of cortisol in the urine

Sometimes blood tests

Severe hyperthyroidism (thyroid hormone excess)

Restlessness, increased heart rate and blood pressure, tremor, weight loss, and inability to tolerate heat

Measurement of levels of thyroid hormone in the blood

Severe hypothyroidism (thyroid hormone deficiency)

Sluggishness, decreased heart rate and blood pressure, thickened skin, decreased appetite, weight gain, and inability to tolerate cold

Measurement of levels of thyroid hormone in the blood

Structural disorders

Peyronie disease (formation of scar tissue in the erectile tissue of the penis)

Firm tissue in the penis

Often severe curving of the penis during erection

Often pain during intercourse

Only a doctor's examination

Usually ultrasonography of the penis to detect scar tissue

Hypospadias (a birth defect)

Urethra located on the underside of the penis

Only a doctor's examination

Microphallus (a birth defect)

Abnormally small penis

Only a doctor's examination

Psychologic disorders

Depression

Sadness, helplessness, hopelessness, loss of appetite, and problems sleeping

Only a doctor's examination

Performance anxiety or stress

Full erections during sleep and when masturbating

Concern about sexual performance

Sometimes ED occurring only with certain partners or in certain situations

Only a doctor's examination

Other

Drugs (see table Some Commonly Used Drugs That Can Cause Erectile Dysfunction)

History of taking a drug known to cause ED

Only a doctor's examination

Hypoxemia (chronically low blood oxygen levels)

Usually a chronic lung disorder (for example, chronic obstructive pulmonary disease)

Pulse oximetry (measurement of the level of oxygen in the blood)