Far more common than people admit
Pain during sex — dyspareunia — affects a substantial proportion of women at some point, and occurs in men too. It is never something to put up with, it is not "in your head", and the great majority of causes can be treated. The real problem is that many women wait years before mentioning it, and some resign themselves to painful sex indefinitely.
The commonest causes in women
- Insufficient lubrication, from short foreplay, stress, hormonal contraception, breastfeeding or menopause. The easiest cause to fix (see choosing a lubricant).
- Vaginismus: involuntary tightening of the pelvic floor muscles making penetration painful or impossible. It responds very well to treatment combining pelvic floor physiotherapy and psychological support.
- Infections: thrush, urinary infection, STIs. Pain with burning, unusual discharge or itching warrants a check.
- Endometriosis, which typically causes deep pain during sex alongside very painful periods. It affects roughly one in ten women of reproductive age and is still diagnosed years late — an average of seven to eight years.
- Vulvodynia and vestibulodynia (pain at the entrance on light touch), dryness from medication, or the after-effects of childbirth or surgery.
In men
Pain may come from infection (urethritis, prostatitis), a tight frenulum that pulls during sex, phimosis, skin irritation, or less often Peyronie's disease (an acquired painful curvature). These are treatable, often simply.
When to seek help without waiting
Pain persisting beyond a few occasions, bleeding, burning, fever, sudden onset where everything was previously fine, or impossible penetration: see a GP, sexual health clinic, gynaecologist or midwife. In most countries you can go directly to a sexual health clinic without a referral from your doctor.
What helps meanwhile
Longer foreplay, generous water-based lubricant, changing position to control depth and pace — and above all stopping as soon as pain appears rather than pushing through. Persisting maintains a vicious circle: the body anticipates, tightens, and the pain increases next time.
Finally, pain concerns the couple and not only the person feeling it: talking about it prevents misunderstandings ("she's gone off me") and allows you to look for solutions together.