Most men have an occasional night when an erection does not happen or does not last. When it starts to happen more often, it is natural to worry, and also natural to put off talking about it. Erection problems are common, they often have a physical side that is worth checking, and a few blood tests can be a practical place to start. This guide explains what those tests look at and why.
How common is it?
The NHS describes erectile dysfunction as very common, particularly in men over 40, and usually nothing to worry about when it happens occasionally (NHS, Erectile dysfunction). LML notes that an estimated 48% of men have difficulty getting or keeping an erection at least some of the time. Stress, tiredness and alcohol are frequent causes of occasional problems, and some medicines can contribute too.
When it happens often, the NHS lists possible causes such as high blood pressure, high cholesterol, diabetes, depression or anxiety, and hormone problems. LML adds that, although psychological causes are behind many cases, it is important to look for physical causes, which fall mainly into two groups: circulation and hormones.
Why circulation matters
An erection depends on healthy blood flow. A 2019 review in Sexual Medicine Reviews describes erectile dysfunction as an independent marker of cardiovascular risk, which can sometimes reflect changes in the arteries in men who have no other symptoms (Miner et al., 2019). That is one reason guidelines suggest looking at blood sugar and cholesterol when erection problems are persistent.
A review in the Medical Journal of Australia lists the tests usually considered: fasting glucose and a fasting lipid profile for all men, and, in selected cases, total testosterone and PSA (McMahon, 2019). The European Association of Urology's 2025 guideline update likewise sets out a structured assessment for erectile dysfunction (Salonia et al., 2025).
What the Erectile Dysfunction Impotence Profile includes
The Erectile Dysfunction Impotence Profile from LML brings these markers into one request:
- Glucose and HbA1c: LML notes that diabetes can affect both circulation and nerves.
- Cholesterol profile: total, LDL, HDL, non-HDL cholesterol and triglycerides, for the circulation side.
- Testosterone, SHBG and albumin, with calculated free testosterone, for the hormonal side.
- Prolactin: high levels can lower testosterone.
- TSH: thyroid function.
- PSA: LML includes it because prostate problems can also contribute to erection difficulties.
If the main question is about testosterone, the Testosterone Plus Profile covers total and free testosterone with SHBG on its own. Remember to take the sample in the morning, between 7am and 10am, as LML advises for testosterone.
What the results can and cannot tell you
Normal results are reassuring, but they do not mean the problem is "in your head". Many men have normal tests and still benefit from support, and stress, sleep and relationships matter. On the other hand, a raised glucose or cholesterol is useful to know about for its own sake, beyond its link with erections.
The NHS lists lifestyle changes that can help, such as losing weight if needed, stopping smoking, regular exercise and cutting down on alcohol. Effective treatments exist. McMahon (2019) notes that 60% to 65% of men with erectile dysfunction, including those with diabetes or high blood pressure, respond to the main oral medicines. A GP or a sexual health clinic can talk through the options (NHS, Erectile dysfunction).
