Erectile Dysfunction and Diabetes: Why Blood Sugar Affects Erections

Many men first learn they have type 2 diabetes because of a change in the bedroom, not a blood test. Erectile dysfunction (ED) is one of the more common complications of diabetes, and it often appears earlier and more severely than in men without the condition. The good news is that the link works in both directions: better blood sugar control, a healthier lifestyle and the right medical care can improve erections for many men. This guide explains how diabetes affects erections, how to tell whether your ED may be related, what to ask your GP, and what treatment options exist in Australia.

General information only. This article does not replace advice from a doctor, pharmacist or diabetes educator.

Key takeaways

• Men with diabetes are more likely to develop ED, and often develop it at a younger age, than men without diabetes.
• High blood glucose over time damages both the blood vessels and the nerves that an erection depends on.
• ED can be an early sign of undiagnosed type 2 diabetes, so persistent ED is a good reason to have your blood glucose checked.
• Blood glucose, blood pressure and cholesterol control, quitting smoking, regular activity and a healthy weight all support erectile function.
• ED medicines are prescription-only in Australia, often work less predictably in diabetes, and are not safe for everyone. They should follow a proper assessment.

In this article

• How common is ED in men with diabetes?
• How diabetes affects erections
• Could ED be a sign of undiagnosed diabetes?
• Other factors that add to the problem
• Blood sugar control and erections
• What to expect at the GP
• Lifestyle changes that help
• Treatment options
• A note on unverified online medicines
• The emotional side
• Questions to ask your doctor
• FAQs

How common is ED in men with diabetes?

Research from many countries consistently shows that ED is more common in men with diabetes than in men without it. Studies commonly report that a large share of men with diabetes, sometimes around half, have some degree of ED, and that on average it starts earlier in life. Exact figures vary by study, age group, type of diabetes and how long a man has lived with the condition, so it is more useful to understand the pattern than to focus on a single number.

The risk tends to rise with how long you have had diabetes and with how poorly it has been controlled. That said, ED is not inevitable. Many men with diabetes keep good erectile function, especially when blood glucose, blood pressure and cholesterol are well managed.

How diabetes affects erections

An erection needs several systems to work together: the brain, nerves, hormones and blood vessels. Diabetes can interfere with several of them at once.

Blood vessel damage

When an erection begins, the lining of the penile arteries (the endothelium) releases nitric oxide, which relaxes the vessel walls so blood can flow in. Persistently high blood glucose damages the endothelium and reduces nitric oxide. The vessels then respond less well, and less blood reaches the erectile tissue. Diabetes also speeds up atherosclerosis, the build-up of plaque in artery walls, which can further limit blood flow.

Nerve damage (neuropathy)

Nerves carry the signals from the brain and spinal cord that start and maintain an erection. Over time, high blood glucose can damage nerves throughout the body, a complication called diabetic neuropathy. When the nerves supplying the penis are affected, the signals may be weaker or delayed. Neuropathy can also affect sensation, bladder function and, in some men, ejaculation. A man may notice that arousal feels reduced, even when desire is still there.

Hormonal changes

Low testosterone is more common in men with type 2 diabetes and obesity. Testosterone mainly supports sexual desire, but low levels can contribute to erectile difficulty and tiredness. Not every man with diabetes and low desire has low testosterone, so testing should be guided by symptoms and a doctor’s assessment.

Smooth muscle and tissue changes

Long-term diabetes may also affect the smooth muscle and connective tissue inside the penis, making it harder for the tissue to expand and trap blood. This is one reason some men with long-standing diabetes find that treatment responses are less predictable.

Could ED be a sign of undiagnosed diabetes?

Yes, it can be. Type 2 diabetes often develops slowly, and many people live with raised blood glucose for years without knowing. ED may be one of the first noticeable effects. If you have persistent ED, particularly with other symptoms or risk factors, it is reasonable to ask for a blood glucose test.

Symptoms that may suggest high blood glucose include:

• Increased thirst and frequent urination, including at night.
• Unusual tiredness.
• Blurred vision.
• Cuts or sores that heal slowly.
• Frequent infections, such as thrush or skin infections.
• Unexplained weight change.

Risk factors include a family history of type 2 diabetes, being overweight (especially around the waist), being over 40, having high blood pressure or high cholesterol, a history of gestational diabetes in a partner (which can signal shared family and lifestyle patterns), and belonging to a population at higher risk, including Aboriginal and Torres Strait Islander peoples and people of certain Pacific, Asian and Middle Eastern backgrounds. Diabetes Australia offers a free online risk assessment based on the Australian Type 2 Diabetes Risk Assessment Tool (AUSDRISK), which can give you an idea of your risk before you see a doctor. It is not a diagnosis.

Diagnosis is made with blood tests such as fasting plasma glucose or HbA1c, interpreted by a doctor. Do not try to diagnose yourself from symptoms or home readings.

Other factors that add to the problem

ED in men with diabetes rarely has just one cause. Several other factors commonly overlap:

• High blood pressure and high cholesterol. These often accompany diabetes and further damage blood vessels.
• Heart disease risk. ED in a man with diabetes can be a marker of broader vascular disease and is a good prompt to review overall heart risk.
• Obesity and inactivity. Both worsen insulin resistance and reduce vascular health.
• Smoking and heavy alcohol use. Both damage blood vessels and nerves.
• Depression, anxiety and diabetes distress. Living with a chronic condition is demanding, and mental health problems commonly affect sexual function.
• Medicines. Some blood-pressure tablets, antidepressants and other medicines can affect erections. Do not stop any prescribed medicine without talking to your doctor.
• Sleep apnoea. It is common in men with type 2 diabetes and is linked to ED.
• Kidney disease. Diabetic kidney disease can contribute to sexual difficulties.

Because the causes overlap, a thorough assessment is more useful than treating the erection problem alone. Our article on what causes weak erections and how they can be treated covers many of these contributors.

Blood sugar control and erections

There is good evidence that long-term blood glucose control reduces the risk of diabetes complications, including nerve and blood-vessel damage. It is therefore reasonable to expect that better control helps protect erectile function, although improvement in ED is not guaranteed and depends on how much damage has already occurred.

Some practical points:

• Targets are individual. HbA1c goals differ between people depending on age, other conditions and risk of low blood sugar. Your doctor or diabetes educator will set a target that suits you.
• Consistency matters. Large swings in blood glucose, as well as persistently high readings, can harm vessels and nerves.
• Take medicines as prescribed. If you think a diabetes medicine is affecting your sexual health, speak to your doctor instead of stopping it.
• Treat the whole risk profile. Blood pressure, cholesterol and smoking matter as much as glucose for vascular health.

If you notice other changes, such as numbness or tingling in your feet, bladder problems, or changes in ejaculation, mention these as well, since they may point to neuropathy.

What to expect at the GP

Many men feel embarrassed to raise ED, but GPs and diabetes educators discuss it routinely. If you already have diabetes, it is worth bringing up at your regular review. A typical assessment may include:

1. A conversation about when the problem started, whether it happens every time, whether you still wake with erections, and how it affects you and your relationship.
2. A review of your health and medicines, including diabetes duration, past HbA1c results, blood pressure, heart history, smoking, alcohol and mood.
3. A physical examination, including blood pressure, weight and waist measurements, and possibly checks for nerve function in the feet and a genital examination.
4. Blood tests, such as HbA1c or fasting glucose, cholesterol, kidney function and, if appropriate, morning testosterone.
5. A cardiovascular risk review, since ED and diabetes both raise the chance of heart and vessel disease.

Your doctor may also suggest a referral to an endocrinologist, urologist, psychologist or sexual health clinician depending on the findings. Seek urgent help (call 000) for chest pain, sudden breathlessness or signs of stroke.

Lifestyle changes that help

Lifestyle changes help both diabetes and erections, and they work alongside any medicines.

• Be active. Regular aerobic activity and strength training improve insulin sensitivity, blood pressure and weight. See our article on whether exercise helps erectile dysfunction. If you have heart disease, neuropathy or other complications, check with your doctor before starting a new program.
• Eat for your blood vessels and glucose. A Mediterranean-style pattern with plenty of vegetables, legumes, wholegrains, fish, nuts and olive oil, and limited processed foods and sugary drinks, is associated with better cardiovascular and metabolic health. A trial published in JAMA in 2004 found that obese men with ED who followed a structured program of diet and exercise had improvements in erectile function compared with a control group. An accredited practising dietitian can tailor advice to your diabetes.
• Lose excess weight. Even modest weight loss can improve blood glucose, blood pressure and erections.
• Stop smoking. Quitline (13 78 48) offers free support in Australia.
• Limit alcohol. Heavy drinking affects erections, nerves and blood glucose control.
• Sleep well. Poor sleep and untreated sleep apnoea worsen both diabetes and sexual function.
• Look after your mental health. Stress, anxiety and low mood are common with diabetes. Talk to your GP, and consider support from services such as Beyond Blue (1300 22 4636) or Men’s Line Australia (1300 78 99 78).
• Use the diabetes support available. Diabetes educators, dietitians and the NDSS can help with day-to-day management.

Treatment options

Treatment depends on the causes, your overall health and your preferences. It usually combines better diabetes and risk-factor control with one or more specific ED treatments.

PDE5 inhibitor medicines

Sildenafil, tadalafil and vardenafil are the main tablets used for ED. They enhance the effect of nitric oxide and help blood flow into the penis when a man is sexually aroused. They do not cause an erection on their own and do not treat diabetes. Points specific to diabetes include:

• Response can be lower. Men with diabetes, especially long-standing or poorly controlled diabetes, often respond less well than other men, although many still benefit. A doctor may adjust the choice or dose.
• They need a prescription in Australia and an assessment of safety first.
• Nitrates must never be combined with them. This includes glyceryl trinitrate spray or tablets used for angina. The combination can cause a dangerous fall in blood pressure.
• Other medicines and conditions matter. Alpha-blockers, some blood-pressure medicines, heart disease, low blood pressure, kidney or liver disease and some eye conditions affect suitability. Diabetes-related eye disease should be mentioned to your doctor.
• Side effects occur, including headache, flushing, indigestion, nasal congestion, dizziness and visual changes. A painful erection lasting more than four hours or sudden loss of vision or hearing needs urgent medical help.

Other options

• Vacuum erection devices, which draw blood into the penis, held with a ring.
• Intracavernosal or intraurethral medicines, used under specialist guidance.
• Testosterone treatment, considered only where low testosterone is confirmed and appropriate.
• Counselling or sex therapy, useful where anxiety, depression or relationship strain contribute.
• Surgery, including penile implants, reserved for selected men when other treatments fail.

Our overview of the latest treatments for erectile dysfunction discusses these options further.

A note on unverified online medicines

For a man with diabetes, who often has heart, kidney or nerve complications and takes several medicines, getting ED treatment without a proper assessment carries extra risk.

• Regulatory status. Sildenafil and similar medicines are prescription-only in Australia. A product name on a website does not mean it is listed on the Australian Register of Therapeutic Goods (ARTG). The TGA is the authority for confirming what is approved. Our article on the legal position of Kamagra oral jelly in Australia explains this in more detail.
• Quality and contents. Unregistered products have not been assessed by Australian regulators, and counterfeits may contain incorrect amounts of active ingredient or other substances. See our guide on how to spot fake Kamagra oral jelly.
• No safety check. A nitrate medicine, low blood pressure, heart disease or kidney problem can make an ED medicine unsafe, and an online purchase does not screen for these.
• Importing rules. The TGA has requirements for importing prescription medicines for personal use, which generally involve a valid prescription. Check current TGA guidance first.

The safest approach is to discuss any ED medicine with your doctor or pharmacist, who can check it against your diabetes medicines and other conditions.

The emotional side

ED can feel isolating, and in a man with diabetes it can add to the strain of managing a chronic condition. Some men feel ashamed, withdraw from intimacy, or become anxious about performance, which can make erectile difficulty worse. Partners may misread the change as loss of interest.

It often helps to talk openly with your partner, explain that ED is a recognised medical complication and not a reflection of attraction, and consider seeing your GP together or attending counselling. Many couples find that broadening what intimacy means, including touch, closeness and other sexual activity, reduces pressure while treatment takes effect.

Questions to ask your doctor

• Could my ED be linked to my blood glucose, nerves, blood pressure or cholesterol?
• What are my HbA1c, blood pressure and cholesterol targets?
• Do I have signs of nerve or kidney complications?
• Could any of my medicines, diabetes or otherwise, be contributing?
• Is an ED medicine safe for me, given my heart, eyes, kidneys and other medicines?
• Should I have my testosterone checked?
• Would counselling or a referral help?
• When should I have a follow-up?

Frequently asked questions

Does everyone with diabetes get ED?

No. The risk is higher, but many men with diabetes never develop significant ED, particularly when their glucose, blood pressure and cholesterol are well controlled.

Can ED be the first sign of diabetes?

It can be. Because type 2 diabetes can go unnoticed for years, persistent ED is a good reason to have your blood glucose tested.

Can better blood sugar control reverse ED?

It can help some men, especially when damage is limited and other factors such as weight, smoking and fitness also improve. If damage is advanced, other treatments may still be needed.

Do ED medicines work in diabetes?

Often, but response can be lower than in men without diabetes. A doctor can advise on the best option and dose.

Are ED medicines safe with diabetes medicines?

Many people with diabetes can use them, but safety depends on the whole picture, including heart disease, blood pressure, kidney function and other medicines. Never combine them with nitrates. Ask your doctor or pharmacist.

Is ED in type 1 diabetes different?

ED can occur in both types. In type 1 diabetes it is more likely to appear after many years of diabetes, and it is strongly linked to complications such as neuropathy.

Where can I find reliable information?

Diabetes Australia, the NDSS, Healthdirect (1800 022 222), Healthy Male and your GP or diabetes educator.

Conclusion

Diabetes can affect erections by damaging blood vessels and nerves, altering hormones and adding stress, but that damage is not always permanent or inevitable. Persistent ED may be a first sign of undiagnosed diabetes, so it is worth testing your blood glucose and heart risk. Managing blood glucose, blood pressure and cholesterol, staying active, quitting smoking and looking after your mental health all support better erections. When medicines are needed, choose them with your doctor so they are safe for you and sourced through regulated channels.

References and further reading

• Diabetes Australia. Type 2 diabetes information and risk assessment. https://www.diabetesaustralia.com.au
• Healthdirect Australia. Erectile dysfunction. https://www.healthdirect.gov.au/erectile-dysfunction
• Healthy Male (Andrology Australia). Erectile dysfunction and diabetes information. https://www.healthymale.org.au
• Therapeutic Goods Administration. Australian Register of Therapeutic Goods and personal importation of medicines. https://www.tga.gov.au
• Esposito K, et al. Effect of lifestyle changes on erectile dysfunction in obese men: a randomized controlled trial. JAMA. 2004;291(24):2978-2984.
• Kamenov ZA. A comprehensive review of erectile dysfunction in men with diabetes. Exp Clin Endocrinol Diabetes. 2015;123(3):141-158.