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Erectile Dysfunction (ED) Tests: NPT, Venous Leak and More

Kelly Brown MD, MBA

Reviewed by Kelly Brown MD, MBA

Written by Geoffrey C. Whittaker

Published 10/26/2020

Updated 06/13/2024

Erectile dysfunction (ED) is a common issue affecting men of all ages. According to the National Institutes of Health, around 30 million men in the United States are affected by erectile dysfunction to varying degrees — but how do you know if you’re one of them?

Self-testing for ED and other sexual health issues isn’t necessarily difficult. You can do some tests at home or simply log your sexual history of erectile dysfunction symptoms until you feel it’s time to talk to a healthcare provider. If you want to get your sex life back on track, though, a formal ED test might make things move a little faster.

Below, we’ve covered the most common test types and how they work, as well as what an ED doctor can do to help you figure out what health problems, hormonal problems, or mental health conditions could be affecting you.

While erectile dysfunction is a common problem, not all men affected share a common cause, so tests may measure or assess different factors to determine if you have ED. As such, there’s no standardized test that can confirm whether or not you have erectile dysfunction, or why it’s occurring. 

Tests currently used to specifically diagnose ED include:

  • Blood work

  • Urine tests

  • Nocturnal penile tumescence (NPT) test

  • Nerve tests

  • Duplex ultrasound test

  • Venous leak test

There are also other ways to gather information and screen for ED using validated questionnaires like the ​​International Index of Erectile Function Questionnaire (IIEF).

Erectile dysfunction can occur for several reasons. Some ED is physical, meaning a physical factor, like your cardiovascular health, affects your body’s ability to supply blood to the soft tissue of your penis.

Common physical causes of ED include high blood pressure, thyroid conditions, and other medical conditions that affect blood flow, such as diabetes. Additionally, certain oral medications, like antidepressants, could contribute to ED.

Other cases of ED are psychological. If you have psychological ED, things like stress, low self-esteem, or sexual performance anxiety may make it more difficult to get and maintain an erection, even when you’re sexually stimulated.

Healthcare providers will perform physical exams to check for things that may contribute to erectile dysfunction, such as high blood pressure, high blood sugar, or health issues affecting blood circulation.

But an erectile dysfunction test (or an erection self-test) can help figure out if you have physical or psychological causes of ED — sometimes. 

Urology experts look for everything from damage at the base of the penis to chronic issues affecting the blood vessels to malfunctioning penile implants to side effects of medications.

When you talk to a urologist or another healthcare provider about treating ED, they’ll likely discuss your symptoms with you to determine the best treatment. And there may not be an official “ED test” involved in the process of ED treatment.

As for the specific tests, keep reading to see how these are performed.

Your healthcare provider may do some blood work to figure out what’s going on with you and your health. They may order various blood tests to check for low testosterone levels and other hormone deficiencies, thyroid function, cardiovascular health issues, diabetes, liver and kidney function and other factors that could contribute to erectile dysfunction. 

After your healthcare provider orders these tests, they might refer you to a urologist for further evaluation.

The two most common types of blood tests are a complete blood count test (CBC test), which tests the levels of all types of blood cells in your body, and a blood sugar test, which measures the amount of glucose in your blood.

Others include a lipid profile, liver function tests, and an HbA1c (hemoglobin A1C) test to screen for diabetes.

While it’s not an incredibly common way of diagnosing ED, a urine test can reveal information about your hormone levels, kidney function, diabetes, and other things that may contribute to erectile dysfunction.

These tests also look for factors like out-of-whack glucose levels or UTIs (urinary tract infections) that can contribute to erectile dysfunction.

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One of the oldest erectile dysfunction tests is the nocturnal penile tumescence test, also known as an NPT test.

We’re giving it a lot of text here because it’s commonly discussed — but before we get into the specifics, we want to be clear: The NPT test is outdated and not really very accurate.

So while it’s generally considered outdated (and isn’t perfectly accurate), the nocturnal penile tumescence test may help you work out whether your ED is caused by a physical factor or a psychological one.

The real value of NPT testing is confirming that you can get hard. This would tell you your sexual activity problems aren’t about sexual desire (i.e., possible low testosterone) or physiological issues, but that they could be rooted in a psychological issue, like anxiety or depression.

The NPT test works by monitoring your ability to get an erection while you sleep. All men with normal, healthy physiological erectile function will get spontaneous erections during sleep — a phenomenon referred to as nocturnal penile tumescence. Sometimes, this will spill over into your early waking hours too — what’s known as morning wood.

If the NPT test shows that you don’t get erections while sleeping, it could indicate that your sexual dysfunction symptoms are linked to a physical health factor. 

By itself, the NPT test doesn’t confirm that you have erectile dysfunction or that a certain factor is causing it. In fact, you’ll get almost as much information by just keeping a notebook to track your morning wood.

Erectile nerve tests are a specific kind of ED test designed to ensure your difficulties getting hard aren’t due to a lack of penis sensitivity. ED nerve testing determines nerve sensitivity and function in your penis by sending small vibrations on the left and right sides of the penile shaft.

If the penis doesn’t react to the vibrations, nerve damage might be the cause of erectile dysfunction. A positive result could mean anything from a pinched nerve to neurological ED.

These results might be the cause of  spinal cord injuries or other nervous system issues. One particular kind of nerve test is the bulbocavernosus reflex or glans sensitivity test, which measures the nerve stimulation in your penis and spinal cord segments. To perform this test, pressure is applied to the glans penis, and anal contraction is observed.

Another type is the penile biothesiometry test. However, there’s no commonly agreed-upon format for this test, so it may look different from one professional to another.

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Duplex ultrasound testing (sometimes called doppler ultrasound testing) evaluates how effectively blood flows through your veins and arteries. This tells you if there’s a problem in your intracavernosal passages — the ones that fill with blood to make you hard.

This test may show tissue scarring, hardening of the arteries, and other physical factors that contribute to erectile dysfunction.

During this test, a small needle is used to inject the penile tissue with a vasodilator. Next, an ultrasound wand is pressed to the side of the penis, allowing for echo waves to be collected.

Using the pitch of the echoes, the ultrasound can determine how effectively blood is flowing through your blood vessels.

If ultrasound tests come back positive, venous leak testing might help you locate the source of leaks — something that’s prevalent in ED at age 40.

Other tests that might be used to diagnose ED include cavernosography and dynamic infusion cavernosometry. These assessments can help locate and identify a venous leak (blood loss from the erectile tissue).

They could also involve vasoactive injection (injecting medication into the penis to induce an involuntary erection) or arteriography (imaging of blood vessels within the penis.

You can absolutely test yourself for ED at home, and you won’t need any special equipment to screen for high cholesterol or vascular disease to do it. Home ED testing is as simple as keeping a record of any patterns of dysfunction, and seeing if they meet the required criteria.

The requirement is a pattern of sexual intimacy where you’ve failed to get or maintain an erection to the satisfaction of yourself or your sexual partner. If that happens several times, you have a pattern.

Here’s the problem: Your recordings won’t help you identify possible causes, nor will they identify potential treatment options. So it may make sense to talk to a professional first.

While erectile dysfunction can be frustrating and stressful, it’s usually treatable through the use of medication, lifestyle changes, and other treatment options. But to get to the treatment part of ED, you have to first get diagnosed.

From the psychological causes to the physiological ones, there’s more value in talking to a healthcare provider sooner than later — especially since they’ll be able to get you started on treatments (and possibly without wasting time on tests).

Treatment may look different depending on your individual circumstances. For some men, it may come in the form of medication like sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra), or avanafil (Stendra). Or it might take the form of online therapy for psychologically-caused ED and sexual anxiety.

Some guys may just need to learn how to relax during sex. Others may need to address health issues, cardiovascular concerns, obesity, or other lifestyle causes of ED.

Testosterone replacement and treatment for prostate cancer might also affect  ED, depending on what’s going on. Making certain changes to your lifestyle, such as exercising more, quitting smoking, or losing weight, may help improve your erectile health and reduce the severity of your erectile dysfunction.

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Dealing with erectile dysfunction can be especially stressful. And if we remember anything from high school and college, it’s that tests usually just add to stress and anxiety. 

The good news is that you may not need to do any tests at all. Here’s what to keep in mind:

  • ED testing isn’t always necessary. Problems like heart disease, mental health issues, kidney disease, and even injuries to the penis in the form of Peyronie’s disease can cause ED. But these conditions must be diagnosed by a healthcare professional.

  • Not all ED tests are very reliable (we’re looking at you, NPT).

  • Since erectile dysfunction is almost always treatable, you may need to determine the exact cause of your problems with help from a healthcare provider before finding the right treatment plan.

  • With medication, psychotherapy, lifestyle changes, or a combination of different erectile dysfunction treatments, you should be able to recover your game.

  • If you have an underlying medical condition that can contribute to erectile dysfunction, such as hypertension (high blood pressure), your healthcare provider might recommend treating it first. That’s why it’s important to discuss your medical history and any current health conditions with your provider.

Ready to get to the heart of the matter? We can help. Our online therapy, medication and other resources are just a few clicks away, including some great options like hard mints chewable ED meds.

10 Sources

  1. U.S. Department of Health and Human Services. (n.d.-g). Treatment for erectile dysfunction - NIDDK. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/urologic-diseases/erectile-dysfunction/treatment.
  2. Sooriyamoorthy T, Leslie SW. Erectile Dysfunction. [Updated 2023 May 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK562253/.
  3. Wiggins, A., Farrell, M. R., Tsambarlis, P., & Levine, L. A. (2019). The Penile Sensitivity Ratio: A Novel Application of Biothesiometry to Assess Changes in Penile Sensitivity. The journal of sexual medicine, 16(3), 447–451. https://pubmed.ncbi.nlm.nih.gov/30773499/.
  4. Kirby, M., Chapple, C., Jackson, G., Eardley, I., Edwards, D., Hackett, G., Ralph, D., Rees, J., Speakman, M., Spinks, J., & Wylie, K. (2013). Erectile dysfunction and lower urinary tract symptoms: a consensus on the importance of co-diagnosis. International journal of clinical practice, 67(7), 606–618. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3748789/.
  5. Betjes, E. (2014b, July 1). What is the Nocturnal Penile Tumescence (NPT) test?. ISSM. https://www.issm.info/sexual-health-qa/what-is-the-nocturnal-penile-tumescence-npt-test/.
  6. U.S. Department of Health and Human Services. (n.d.-a). Definition & Facts for erectile dysfunction - NIDDK. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/urologic-diseases/erectile-dysfunction/definition-facts.
  7. U.S. Department of Health and Human Services. (n.d.-a). Diagnosis of Erectile Dysfunction. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). https://www.niddk.nih.gov/health-information/urologic-diseases/erectile-dysfunction/diagnosis
  8. U.S. Department of Health and Human Services. (n.d.-a). Symptoms & Causes of Erectile Dysfunction. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). https://www.niddk.nih.gov/health-information/urologic-diseases/erectile-dysfunction/symptoms-causes
  9. Queremel Milani DA, Jialal I. Urinalysis. Treasure Island (FL): StatPearls Publishing. (2023). https://www.ncbi.nlm.nih.gov/books/NBK557685/
  10. Miller TA. Diagnostic Evaluation of Erectile Dysfunction. Am Fam Physician. (2000). https://www.aafp.org/pubs/afp/issues/2000/0101/p95.html
Editorial Standards

Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references. See a mistake? Let us know at [email protected]!

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.

Kelly Brown MD, MBA
Kelly Brown MD, MBA

Dr. Kelly Brown is a board certified Urologist and fellowship trained in Andrology. She is an accomplished men’s health expert with a robust background in healthcare innovation, clinical medicine, and academic research. Dr. Brown was previously Medical Director of a male fertility startup where she lead strategy and design of their digital health platform, an innovative education and telehealth model for delivering expert male fertility care.

She completed her undergraduate studies at University of North Carolina at Chapel Hill (go Heels!) with a Bachelor of Science in Radiologic Science and a Minor in Chemistry. She took a position at University of California Los Angeles as a radiologic technologist in the department of Interventional Cardiology, further solidifying her passion for medicine. She also pursued the unique opportunity to lead departmental design and operational development at the Ronald Reagan UCLA Medical Center, sparking her passion for the business of healthcare.

Dr. Brown then went on to obtain her doctorate in medicine from the prestigious Northwestern University - Feinberg School of Medicine and Masters in Business Administration from Northwestern University - Kellogg School of Management, with a concentration in Healthcare Management. During her surgical residency in Urology at University of California San Francisco, she utilized her research year to focus on innovations in telemedicine and then served as chief resident with significant contributions to clinical quality improvement. Dr. Brown then completed her Andrology Fellowship at Medical College of Wisconsin, furthering her expertise in male fertility, microsurgery, and sexual function.

Her dedication to caring for patients with compassion, understanding, as well as a unique ability to make guys instantly comfortable discussing anything from sex to sperm makes her a renowned clinician. In addition, her passion for innovation in healthcare combined with her business acumen makes her a formidable leader in the field of men’s health.

Dr. Brown is an avid adventurer; summiting Mount Kilimanjaro in Tanzania (twice!) and hiking the incredible Torres del Paine Trek in Patagonia, Chile. She deeply appreciates new challenges and diverse cultures on her travels. She lives in Denver with her husband, two children, and beloved Bernese Mountain Dog. You can find Dr. Brown on LinkedIn for more information.

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