Erectile dysfunction (ED), commonly referred to as impotence, is a condition where a man has difficulty achieving or maintaining an erection sufficient for satisfactory sexual performance. While occasional difficulty with erections is not uncommon, persistent erectile dysfunction can significantly impact a man’s confidence, intimate relationships, and overall quality of life.

In this in-depth guide, we explore what causes erectile dysfunction in men, based on insights from medical professionals. Whether you’re experiencing symptoms or researching for a loved one, understanding the root causes is the first step toward effective treatment and recovery.

What Is Erectile Dysfunction?

Erectile dysfunction occurs when there’s a consistent inability to achieve or sustain an erection. For a healthy erection, several systems in the body must work in harmony: the nervous system, blood circulation, hormone levels, and emotional health. A disturbance in any of these areas can lead to ED.

ED is not a natural part of aging, although it’s more common in older men. According to studies, around 40% of men over the age of 40 and nearly 70% of men over 70 experience some form of ED. Thankfully, it’s often treatable once the underlying cause is identified.

Top Causes of Erectile Dysfunction in Men

Doctors generally categorize the causes of erectile dysfunction into physical, psychological, and lifestyle-related factors. Often, a combination of these is responsible.

1. Cardiovascular Diseases and Poor Circulation

One of the most common causes of ED is reduced blood flow to the penis. Healthy erections rely on strong blood flow, and any condition that affects the cardiovascular system—such as high blood pressure, atherosclerosis (hardening of the arteries), or high cholesterol—can restrict that flow.

Doctor’s Insight: “Erectile dysfunction can be an early warning sign of heart disease. Men experiencing ED should also get screened for cardiovascular risk factors,” says Dr. Robert Manning, a urologist with 20+ years of clinical experience.

2. Diabetes

Diabetes is a major contributor to erectile dysfunction. High blood sugar levels over time can damage nerves and blood vessels throughout the body, including those in the penis.

Men with Type 2 diabetes are two to three times more likely to experience ED than those without. Poorly managed blood sugar increases this risk further.

3. Hormonal Imbalances

Hormones play a vital role in sexual function. Low testosterone levels (hypogonadism) can reduce libido and impair erections. Other hormonal disorders, such as thyroid disease or elevated prolactin, can also contribute to ED.

Doctor’s Insight: “A simple blood test can detect hormone imbalances that may be causing ED. Testosterone therapy can often restore function when low levels are the cause,” notes Dr. Ellen Wright, endocrinologist.

4. Neurological Disorders

The brain and nervous system play a critical role in triggering erections. Conditions like Parkinson’s disease, multiple sclerosis, spinal cord injuries, and even stroke can interrupt nerve signals to the penis, leading to erectile dysfunction.

In some cases, nerve damage from prostate surgery (such as for cancer) can also be a cause.

5. Psychological Causes

Sexual arousal begins in the brain, making psychological health just as important as physical health. Common mental health causes include:

• Stress

• Anxiety (especially performance anxiety)

• Depression

• Relationship issues

Even if the root cause is physical, psychological stress can worsen ED symptoms.

6. Medications and Drugs

Several prescription medications list erectile dysfunction as a side effect. These include:

• Antidepressants

• Blood pressure medications

• Anti-anxiety drugs

• Anti-seizure medications

• Certain chemotherapy drugs

Additionally, alcohol, nicotine, and recreational drugs (like cocaine or marijuana) can interfere with erectile function.

7. Obesity and Sedentary Lifestyle

Excess body weight can lead to lower testosterone levels, poor circulation, and an increased risk of diabetes and heart disease—all of which are risk factors for ED. Men who are inactive or overweight are more likely to develop erectile dysfunction at a younger age.

Doctor’s Insight: “Weight loss and regular physical activity can significantly improve erectile function. Even walking 30 minutes a day can make a difference,” emphasizes Dr. Kamal Roy, cardiologist.

8. Sleep Disorders

Sleep apnea and chronic sleep deprivation affect hormone production and vascular health, both of which are essential for sexual performance. Studies suggest that men with untreated sleep apnea are at higher risk for ED.

9. Peyronie’s Disease

Peyronie’s disease is a condition where scar tissue develops inside the penis, causing painful and curved erections. This physical deformity can also lead to ED and is more common in men over 40.