Diabetes and Your Body: Periods, Thrush, Sex and Fertility

TL;DR: Diabetes can make periods less predictable, push blood sugar up in the days before your period, and make thrush and urine infections more likely. It can also cause vaginal dryness and trouble with arousal. If you are thinking about pregnancy, plan ahead: NICE advises high-dose folic acid (5 mg) and getting your HbA1c as close to target as you safely can before you conceive.

When people talk about diabetes, the conversation usually stays with sugar, tablets and feet. What gets left out is everything below the waist. The thrush that comes back every few weeks. The cycle that never quite settles. The sex that has started to hurt, or that you have quietly stopped wanting. The question of whether you can safely have a baby. These are some of the most common ways diabetes shows up in a woman's life, and some of the least discussed in clinic. If you live with type 1 or type 2 diabetes, or you have recently been told your sugar is high, this is the conversation you deserve to have.

Can diabetes affect your periods?

Yes. A 2024 review in the journal Endocrine found that almost 40 percent of women with type 1 diabetes will have reproductive problems at some point, such as irregular periods, raised androgens or fertility difficulties. The same review links diabetes with heavy periods and, in type 2 diabetes, a higher chance of menopause before 45.

The reasons differ by type. In type 2 diabetes, high insulin levels can push the ovaries to make more androgens (the hormones often called "male" hormones), and extra body fat converts some hormones into oestrogen. Together, these can disrupt ovulation and make cycles longer or irregular. This is the same insulin story that sits behind many cases of PCOS, which we unpack in PCOS and insulin resistance. If you have been told you are in the prediabetes range, our guide to prediabetes in women explains what that means for your hormones.

The cycle can also move your blood sugar. In the second half of the cycle, after ovulation, progesterone rises and the body tends to respond less well to insulin. A systematic review of women with type 1 diabetes found that some women see higher readings and lower insulin sensitivity in this luteal phase, although the evidence is mixed, so any change to your insulin should be based on your own pattern and agreed with your diabetes team. If your numbers drift up for no clear reason, check where you are in your cycle before you blame yourself or your food. For the wider picture on hormones and glucose, see blood sugar and hormones.

Why does thrush keep coming back when you have diabetes?

Yeast feeds on sugar. When blood glucose runs high, more sugar reaches the tissues and fluids of the vagina, and yeast organisms can grow more easily. The NHS lists poorly controlled diabetes as one of the main reasons thrush returns.

There is a second, newer reason. A group of diabetes medicines called SGLT2 inhibitors, which include dapagliflozin and empagliflozin, work by passing extra sugar out through your urine. They protect the heart and kidneys, but thrush is one of their listed side effects. If you started one of these and the itching followed, tell your doctor or pharmacist rather than stopping it on your own. Good hygiene, loose cotton underwear and treating thrush early usually help, and your clinician can review your options.

Thrush that keeps coming back, which the NHS defines as more than four times in 12 months, is worth a proper check rather than another pharmacy cream. Sometimes it is not thrush at all, and BV or an STI can look similar. Our guide to vaginal infections, yeast and BV walks through the differences.

Urine infections and your bladder

Women with diabetes also have a higher risk of urinary tract infections. High sugar in the urine gives bacteria a better environment, and over time diabetes can damage the nerves that tell you when your bladder is full and when it has emptied. Urine left sitting in the bladder is more likely to become infected. The NIDDK advises seeing a doctor promptly if you have frequent, urgent or painful urination.

Do not sit on a UTI when you have diabetes. Fever, pain in your back or side, shivering or vomiting can mean the infection has reached your kidneys, and that needs same-day care. Our UTI guide for women covers prevention and when to seek help.

Diabetes, desire and comfort during sex

This is the part many women never mention to their doctor. Diabetes can cause trouble with arousal, vaginal dryness and painful sex, partly through nerve damage. The nerves that trigger lubrication during arousal can be affected, so your mind may be willing while your body does not respond the way it used to. Add the tiredness of high sugars, low mood, worry about a hypo during sex, or a recent thrush flare, and it makes sense that intimacy can feel like one more thing to manage.

A few things help. A water-based or silicone lubricant can make a big difference to dryness. Steadier blood sugar over time protects the nerves and blood vessels involved. If sex is painful, or you have lost interest and it bothers you, raise it with your clinician: it is a recognised complication of diabetes, and there are treatments. If you are close to or past menopause, falling oestrogen adds to dryness, which we cover in vaginal dryness after menopause.

Can you have a healthy pregnancy with diabetes?

Yes, and many women with diabetes do. The key is planning. NICE guidance explains that good blood glucose control before and during pregnancy reduces the risk of miscarriage, congenital malformation, stillbirth and newborn death. The months before you conceive matter as much as the pregnancy itself.

Diabetes can also make conceiving harder. The 2024 Endocrine review notes that women with type 2 diabetes have lower fertility, with one study finding they were about a third less likely to conceive in a given cycle than women without diabetes. Our fertility tips for getting pregnant cover the basics that apply to everyone.

What to do before you try for a baby

The NICE diabetes in pregnancy guideline sets out clear steps for women with pre-existing diabetes:

• Use contraception until you are ready. NICE advises continuing contraception until your blood glucose is well controlled, and confirms that women with diabetes can use oral contraceptives.
• Aim for an HbA1c below 48 mmol/mol (6.5 percent) if you can reach it without troublesome hypos. Any drop towards target lowers the risk to the baby. If your HbA1c is above 86 mmol/mol (10 percent), NICE strongly advises waiting until it comes down.
• Take 5 mg of folic acid a day, not the standard 400 microgram dose, from before conception until 12 weeks of pregnancy, to lower the risk of neural tube defects. This higher dose needs a prescription.
• Review your medicines. Metformin may be continued, but other tablets for diabetes are usually switched to insulin, and statins should be stopped before pregnancy.
• Get your eyes and kidneys checked. NICE recommends a retinal assessment at your first preconception appointment and a kidney check before you stop contraception.

Ask for a referral to a preconception or diabetes antenatal clinic. In Nigeria, Kenya, Ghana or South Africa that may mean a diabetes clinic at a teaching or referral hospital; in the UK, your GP can refer you. If you have never had diabetes but develop high blood sugar in pregnancy, that is gestational diabetes, a related but separate condition, covered in our guide to gestational diabetes.

When to see a clinician

Book an appointment if you have thrush more than a few times a year, periods that have become very irregular or very heavy, pain during sex, or if you are planning a pregnancy. Seek urgent care if you have UTI symptoms with fever, back pain or vomiting, or if you are pregnant with bleeding, severe pain or very high sugars. If you have not been diagnosed but keep getting thrush alongside thirst and tiredness, read the type 2 diabetes symptoms women miss and ask for a blood test.

This post is education, not medical advice. Your diabetes team knows your history and should guide any changes to treatment.

Tracking helps you join the dots. With Asele, cycle tracking and symptom logging can show whether thrush, sugar spikes or low mood cluster around a particular phase of your cycle. You can talk it through with Amara in Yoruba, Hausa, Igbo, Swahili, French or English, and the Health Brief turns your logs into a short summary to take to your appointment, so the conversation starts from evidence. You can find us at Asele.

References

1. Zaimi M, et al. Gonadal dysfunction in women with diabetes mellitus. Endocrine, 2024. pmc.ncbi.nlm.nih.gov
2. Gamarra E, Trimboli P. Menstrual cycle, glucose control and insulin sensitivity in type 1 diabetes: a systematic review. Journal of Personalized Medicine, 2023. pmc.ncbi.nlm.nih.gov
3. NIDDK. Diabetes, sexual and bladder problems. niddk.nih.gov
4. NHS. Thrush in men and women. nhs.uk
5. NHS. Dapagliflozin. nhs.uk
6. NHS. Urinary tract infections (UTIs). nhs.uk
7. NICE. Diabetes in pregnancy: management from preconception to the postnatal period (NG3). nice.org.uk