An erection happens when blood fills the penis. Some blood vessels open wide to let blood flow into the penis. Other blood vessels shrink to keep the blood from leaving the penis. The change in the blood vessels is controlled by nerves.

ED may be caused by:

  • Blood vessel injury or disease
  • Harm to nerves that control blood vessels or feeling in the penis
  • Stress that change how the nerves work—more likely with sudden ED
  • Hormone problems such as low testosterone or thyroid disease
  • Certain medicines such as those that treat high blood pressure, mental health problems, or heart rhythm problems
  • Problems in the penis caused by Peyronie disease, hypospadias, or penile fracture

Risk Factors

ED is more common in those aged 40 years and older. The risk increases with age. Things that increase the risk of ED are:

  • Heart disease risk factors, such as:
  • Overweight and obesity
  • Diabetes
  • High blood pressure
  • High cholesterol
  • Smoking
  • Lack regular physical activity
  • Peripheral neuropathy
  • Prostate problems
  • Surgery on related nerves, spinal cord, blood vessels, or prostate
  • Too much alcohol
  • Use of illegal drugs
  • Certain medicines



The main symptom of ED is not being able to get or keep an erection long enough to have sex.


The doctor will ask about symptoms and health past. A physical exam will be done. This will include a genital and rectal exam.

The doctor will ask about the quality of erections. This may include questions about the time of day, how hard the erection is, and how long it lasts. The doctor may also ask about the person's mental state, desire, arousal, ejaculation, and orgasms. The answers can help point to the source of the problem.

A test can be done at home to check for erections during sleep. Erections during sleep may mean the cause is psychological. Problems with an erection during sleep points to a physical cause.

Other tests may include:

  • Blood tests—to check for health problems such as diabetes, high cholesterol, or low testosterone
  • Doppler ultrasound—to check blood flow in the penis



ED care may involve one or more of these:

Lifestyle Habits

Some changes in daily habits can improve tissue health and blood flow. General steps are:

  • Weight loss, if needed. This can also help balance hormones
  • Quit smoking
  • Regular physical activity
  • Limit alcohol to 2 drinks or less a day
  • Stop illegal drug use
  • Relaxation habits and stress management


ED can be treated with medicine to:

  • Relax muscles and improve blood flow to the penis—cannot be taken with nitrates
  • Boost testosterone levels—only helpful if you have low testosterone

ED medicine can be taken by mouth or as a shot, or be placed on the skin or into the tip of the penis.

Talk to your doctor before taking any over the counter medicine for ED. Some of them may be unsafe.

Vacuum Devices

A vacuum device pulls blood into the penis. A band is placed around the penis to keep the erection.


Surgery can be used to fix blood vessels or other structural problems.

Penile Implants

Implants may be placed in the penis. The implants can be inflated to make an erection when needed.

Penile Implant
penile implant smaller
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Sex Therapy

Sex therapy may help ED caused by:

  • Relationship problems
  • Anxiety
  • Depression

This can be done alone or with a partner.


To help lower the risk of ED:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.