How Erectile Dysfunction Is Diagnosed

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If you or your loved one is seeking treatment for erectile dysfunction (ED), you may be feeling overwhelmed, anxious, or discouraged. But the more knowledgeable you become about the condition, which includes its diagnostic evaluations, exams, and procedures your healthcare provider may recommend, the quicker you can regain a sense of control.

After all, ED is treatable; once you understand what’s going on with your body, you’ll be armed with information to choose a treatment approach that’s best for you.

Erectile dysfunction diagnosis
Illustration by Joshua Seong. © Verywell, 2018.

Self-Checks and At-Home Testing

You have options for performing at-home tests, either on your own or using a device recommended by your healthcare provider.

Nocturnal Penile Tumescence (NPT) Stamp Test

When sleeping, it’s common for a man to average anywhere from three to five erections per night lasting 25 to 35 minutes, according to the National Health Service (NHS) in the United Kingdom.

Researchers don’t fully understand why night-time erections occur, but they believe they’re closely linked to the REM phases of your sleep cycles. Night-time erections can be an indicator that your reproductive system is functioning properly.

For people with ED, there may be an absence of night-time erections. If you’re uncertain as to whether you’re having erections while sleeping, you can try a self-test, as stated by the University of California, San Francisco Medical Center (UCSFMC). The test is called the nocturnal penile tumescence (NPT) stamp test, and it involves wrapping four to six postage stamps of any variety around your penis before you go to sleep and noting changes upon waking up.

Although this specific self-test is considered outdated, if you’ve never discussed ED with a healthcare provider before, it may give you with some talking points to initiate a conversation. Also, there are no risks involved when the self-test is performed correctly.

How to Do a NPT Stamp Test

Here's how to perform the NPT, as outlined by UCSFMC:

  • You’ll need a strip of four to six postage stamps for each night, and you’ll perform the self-test three nights in a row.
  • Wear brief-style underwear with a fly.
  • Position the penis so that it’s through the fly, and keep most of your pubic hair inside the briefs.
  • Using the stamps, make a tight ring around the shaft of the penis. Make sure the stamps overlap so that you can moisten the top one and seal it over the bottom one.
  • Allow the stamps to dry for a minute or two, and reposition the penis back inside the briefs. The underwear will help to hold the stamps in place while you sleep. At first, the stamps may feel a bit strange or uncomfortable.
  • When you awaken, check to see if your stamp ring has torn along any of the perforations. If you awake in the middle of the night and notice you have an erection, UCSFMC recommends checking it and assessing its firmness.

While the stamp self-test may be able to provide you with some information as to whether or not you’re having nightly erections, it can’t provide details as to the quality or duration of them. Ultimately, if you suspect ED, you should make an appointment to see your healthcare provider.


Your healthcare provider may offer you more up-to-date options for at-home testing, like a portable home device called the RigiScan. This device is one you can take home with you and it provides more detailed information, including penile rigidity and engorgement, measured by loops attached to the penis before sleeping.

The data is stored on the portable computing device and can be reviewed and printed on command. Overall, the device is easy to use and requires little training. You should discuss the feasibility and costs with your provider.

Labs and Tests

When you see your healthcare provider, they’ll gather your health history, ask additional follow-up questions regarding your sexual health, and perform a physical exam. In some instances, this may be all the healthcare provider needs to make an accurate diagnosis of ED and provide you with treatment options.

However, if the healthcare provider believes an underlying condition may be contributing to ED, they might suggest additional testing or an appointment with a specialist for the following.

A Physical Examination

The healthcare provider may examine your penis, testicles, patterns of hair loss on certain parts of your body, or the presence of gynecomastia—a condition where the breast tissue in a man swells in response to hormone imbalances.

Your healthcare provider may also examine whether the sensation to the penis and testicles is intact and if there’s adequate blood flow to the area.

Also, your physical assessment could include a rectal exam to evaluate your prostate as well as the tone of the muscles of the pelvic floor. Finally, your healthcare provider might check out your heart and lung function to help determine the best course of action regarding treatment.

Erectile Dysfunction Healthcare Provider Discussion Guide

Get our printable guide for your next healthcare provider's appointment to help you ask the right questions.

Doctor Discussion Guide Man

Blood Tests

If it’s been a while since you’ve seen a healthcare provider, they may choose to run some basic blood work such as a complete blood count (CBC) and a comprehensive metabolic panel (CMP). The data collected from these blood tests provide your practitioner with an overview of how your body is functioning.

Other blood panels your healthcare provider may request include testosterone levels (most accurately done between 8 am and 11 am), a thyroid panel, B12 levels, or other more specific tests that provide insight into your unique situation. Discuss what your healthcare provider hopes to gather from this information.

Urine Test 

Underlying illnesses like diabetes can be responsible for causing or worsening ED. Urine tests screen for the presence of diabetes or other health conditions. If your healthcare provider suspects you have one of these illnesses, they may recommend a urine test or urinalysis.   

Mental Health Evaluation 

Psychological factors like depression or anxiety can cause ED. As a result, your healthcare provider might ask you a series of questions about your mental health. Just try to answer the questions honestly and to the best of your ability so that your practitioner can make appropriate treatment recommendations to support your emotional health and well-being.


If your healthcare provider needs to examine the blood flow to the penis further, they’ll likely do a test in the office using doppler ultrasound. This is often done with the addition of injection of medication (intracavernosal) into the penile corporal bodies to look at blood flow into and out of the penis. Medications include prostaglandin E1 or Trimix which is a mixture of papaverine, phentolamine, and prostaglandin.

Ultrasound technology uses sound waves to create images of what’s going on in your body. A trained ultrasound technician or urologist will hold a small instrument over the blood vessels that supply the penis and gather a series of pictures to identify if there’s diminished blood flow (arterial insuffiiciency) or venous leakage (blood not maintained in penile veins during erection).

Typically, ultrasounds are outpatient tests, and the procedure isn't painful.

Differential Diagnoses

In many instances, once the healthcare provider has reviewed any relevant medical and sexual history and performed a physical exam, they can make a preliminary diagnosis of ED. Some healthcare providers might choose to prescribe a trial dose of an oral medication to treat ED—medications are generally safe for healthy men.

However, if your symptoms of ED are accompanied by another condition like diabetes, high blood pressure, or prostate problems, your healthcare provider will need to take a more in-depth look at your particular situation to determine a plan of care.

Frequently Asked Questions

  • How is erectile dysfunction diagnosed?

    The diagnosis of erectile dysfunction (ED) can often be made based on symptoms alone. Blood tests may be used to check for hormonal problems such as hypogonadism, particularly if the circumstances are unusual (such as ED at a younger age). The healthcare provider may also want to ask about any psychological or emotional issues that may be causing or contributing to ED.

  • How is ultrasound used to diagnose erectile diagnosis?

    A penile Doppler ultrasound can check for blood flow problems using high-frequency sound waves. The test is performed after the penis is injected with a drug to induce an erection. The study can help evaluate for anatomic or psychological causes to the ED.

  • What other tests can help diagnose erectile dysfunction?

    If healthcare providers are unsure if the cause is physiological or psychological, other tests may be ordered to better characterize the condition, including:

    • Bulbocavernous reflex test, used to evaluate penile nerve sensations
    • Cavernosometry, in which fluid is injected into the penis to measure vascular pressure
    • Penile biothesiometry, used to see if your penis responds to vibration
    • Snap gauge penile bands, used to check if you have nighttime erections
  • Can you diagnose erectile function at home?

    A nocturnal penile tumescence (NPT) stamp test can determine if you have nighttime erections. The test involves wrapping a band of four to six postage stamps around the penis before going to sleep and checking for changes the next morning. If the band is broken, it suggests that you have nighttime erections and the cause may be more psychological than physiological.

  • What medical conditions can cause erectile dysfunction?

    There are many conditions your healthcare provider may want to explore, some of which may be serious and require treatment. These include:

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Health Service. Sexual Health: 5 penis facts.

  2. Becher E., Bechara A. (2011) Making the Diagnosis of Erectile Dysfunction. In: McVary K. (eds) Contemporary Treatment of Erectile Dysfunction. Contemporary Endocrinology. Humana Press. doi:10.1007/978-1-60327-536-1_6

  3. Elhanbly S, Elkholy A. Nocturnal penile erections: the role of RigiScan in the diagnosis of vascular erectile dysfunction. J Sex Med. 2012;9(12):3219-26. doi: 10.1111/j.1743-6109.2012.02954.x

  4. Yafi FA, Jenkins L, Albersen M, et al. Erectile dysfunction. Nat Rev Dis Primers. 2016;2:16003. doi:10.1038/nrdp.2016.3

  5. National Institute of Diabetes and Digestive and Kidney Diseases. Diagnosis of erectile dysfunction.

  6. Jung DC, Park SY, Lee JY. Penile Doppler ultrasonography revisited. Ultrasonography. 2018;37(1):16-24. doi:10.14366/usg.17022

  7. Cleveland Clinic. Erectile dysfunction.

  8. Gao L, Tang Z, Qian S, Yuan J. AB132. Nocturnal penile tumescence monitoring; what have we done and what should we do? Trans Androl Urol. 2015 Aug;4(Suppl 1):AB132.

  9. Yafi FA, Jenkins L, Albersen M, et al. Erectile dysfunction. Nat Rev Dis Primers. 2016;2(1):16003. doi:10.1038/nrdp.2016.3

By Jenny Lelwica Buttaccio, OTR/L
Jenny Lelwica Buttaccio, OTR/L, is a licensed occupational therapist and advocate for patients with Lyme disease.