What happened

The coccyx is the small triangle of fused bone at the very base of your spine. In the second stage of labour the baby's head passes directly over it, and the coccyx has to move backwards to let that happen. Ligaments softened by pregnancy allow more movement than usual, which is what makes birth possible — and also what leaves the joint bruised, strained or, less commonly, dislocated or fractured afterwards.

POGP names the region explicitly when describing pelvic girdle pain: pain "in your pubic bone, groin, hips, buttocks and/ or tail bone." So this is a recognised part of the same picture, not an exotic complaint.

It is more likely after a long pushing stage, a large baby, an assisted birth with forceps or ventouse, or a birth in a position that put weight through the base of the spine. It also happens after entirely straightforward births, and after caesareans in people who had coccyx pain during pregnancy.

What it feels like

The signature is exquisitely positional:

Sitting hurts, especially on hard chairs, and especially leaning back.
Standing up from sitting is often the single worst moment.
Sitting on one buttock, or perched forward, becomes automatic.
Opening your bowels hurts, and so does sex.
Lying on your back can be uncomfortable; lying on your side is usually fine.

Pain that is genuinely absent when you are walking and unbearable when you sit is the pattern that distinguishes coccyx pain from general back or pelvic pain.

What is not coccyx pain

Two things get confused with it.

Perineal wound pain. The NHS notes that after an episiotomy or a large tear you will need stitches, and NICE NG194 lists perineal pain that is not resolving or worsening, increasing need for pain relief, discharge with a strong or unpleasant smell, swelling, and wound breakdown as things to report. NG194 requires urgent referral if a perineal wound breaks down — "to be seen the same day." If the pain is at the vaginal opening rather than the bone at the base of your spine, it is the wound.

Piles. Also excruciating to sit on, also common after birth, but felt at the anus rather than on the bone behind it.

You can have all three at once, which is part of why this region is so hard to describe to anyone.

When to get it looked at urgently

POGP says to call your GP straight away or go to A&E if you have pain going down both legs at the same time, numbness in both legs at the same time, difficulty passing urine, leakage of stool from the bowel that you could not control, or numbness around the vagina or back passage.

Separately, the HSE lists severe muscle and joint pain after birth as a possible sign of sepsis, and tummy pain that is severe or getting worse as a possible sign of infection. Escalating pain with a temperature is a same-day call, not a physiotherapy referral.

What actually helps

Most of this is about taking load off the joint while it settles.

How you sit. Sit slightly forward with your weight through your thighs rather than rocked back onto the tailbone. A firm chair is often better than a soft sofa, which lets you sink into exactly the wrong position.
Wedge cushions. A cushion with a cut-out at the back, so the coccyx is unsupported, is more comfortable than a ring cushion for most people.
Avoid the flotation ring for piles. The HSE advises against it for haemorrhoids — sitting on a ring "can give temporary relief but actually make the problem harder to clear" — and suggests instead placing "a folded hand towel under each thigh while sitting," which lifts you slightly and takes pressure off. The same trick works for a sore coccyx.
Do not become constipated. Straining loads the coccyx directly. The HSE's advice is to drink plenty of fluids, eat high-fibre foods, sit bent slightly forward with your feet on a footstool, avoid pushing and breathe out slowly.
Change position often. Long feeds in one position are the main aggravator; alternate between sitting, side-lying and standing.
Pain relief. Ask your GP, midwife or pharmacist what is appropriate for you, especially if you are breastfeeding. No doses here; that is a conversation with a professional.

Getting treated

POGP's referral route applies: speak to your midwife or GP first, and ask to see a specialist pelvic health physiotherapist. NICE NG194 names physiotherapy as one of the services a GP may refer to from the 6 to 8 week postnatal check, so it is a reasonable thing to ask for there.

A specialist physiotherapist can assess coccyx movement, work on the surrounding pelvic floor and gluteal muscles, and advise on positioning. Where pain persists, imaging and specialist injections exist as further options — but they come after conservative treatment, not instead of it.

How long it lasts

No source publishes a reliable timeline for coccyx pain after birth, and it would be dishonest to invent one. What is documented is the pattern of care: POGP says musculoskeletal symptoms after birth "are not normal and should not be 'put up with' in silence" and can be improved with the right advice, and the HSE says to talk to a GP about aches and pains continuing beyond two months. If sitting still hurts at your postnatal check, say so then rather than assuming it is your new normal.

Tailbone Pain After Birth