From the Guidelines
Laboratory tests for impotence, also known as erectile dysfunction, should include blood tests to identify underlying causes, such as hormonal imbalances, diabetes, or cardiovascular issues, and may involve measuring testosterone levels, blood glucose, cholesterol, and lipid profiles, as recommended by the American College of Physicians 1. The tests usually measure:
- Testosterone levels to check for hormonal imbalances
- Blood glucose to check for diabetes
- Cholesterol and lipid profiles to check for cardiovascular issues
- A complete blood count to rule out anemia
- Thyroid function tests to identify thyroid disorders that affect sexual function
- Prostate-specific antigen (PSA) testing may be recommended for men over 50 Additional specialized tests might include:
- Nocturnal penile tumescence testing to determine if erections occur during sleep
- Doppler ultrasound to evaluate blood flow to the penis These tests help healthcare providers determine whether impotence has a physical cause, which is present in about 80% of cases, or if psychological factors are primarily responsible, as noted in the guideline by the American College of Physicians 1. Early morning testosterone testing is particularly important as levels are highest at this time, providing the most accurate assessment, and the American College of Physicians does not recommend for or against routine use of hormonal blood tests or hormonal treatment in the management of patients with erectile dysfunction, due to insufficient evidence to determine net benefits and harms 1. The choice of laboratory tests should be individualized based on the patient's clinical presentation and medical history, and the American College of Physicians recommends that clinicians base the choice of a specific treatment on the individual preferences of men with erectile dysfunction, including ease of use, cost of medication, and adverse effects profile 1.
From the Research
Lab Tests for Impotence
Lab tests for impotence, also known as erectile dysfunction (ED), are essential for determining the underlying cause of the condition. The following are some of the lab tests that may be used to diagnose ED:
- Fasting glucose levels to check for diabetes mellitus 2
- Fasting lipid profile to check for dyslipidaemia 2
- Total testosterone level to check for low testosterone levels 2
- Prostate-specific antigen test to check for prostate-related issues 2
- Nocturnal penile tumescence (NPT) studies to evaluate nocturnal erections 3
- Somatosensory evoked potentials (SSEP) and bulbocavernosus reflex latency (BCR) to evaluate the sacral reflex arc of erection 3
- Penile EMG's to evaluate corporal cavernosal smooth muscle electrical activity 3
- Penile plethysmography, penile blood pressures, penile brachial index, selective internal pudendal pharmacoangiography, Doppler sonography, dynamic infusion cavernosometry/cavernosography, nuclear washout radiography, and color duplex Doppler ultrasound to evaluate penile hemodynamics 3
- Pharmacotesting, which consists of intracavernous injection and visual rating of the subsequent erection 3
Diagnostic Approaches
The diagnostic approach to ED may involve a combination of the following:
- A full medical and personally and culturally sensitive sexual history 2
- A focused clinical examination 2
- Laboratory tests, such as those mentioned above
- A multifaceted comprehensive approach, including history, physical examination, psychologic evaluation, and RigiScan monitoring 4
- Evaluation of reversible factors and lifestyle changes that might help preserve erectile capacity 5
Specific Conditions
Certain conditions, such as diabetes, may require specific diagnostic approaches. For example: