Examination and periodontal charting
We measure the depth of the gum around each tooth, record bleeding and note where the swelling sits. X-rays show whether bone has been lost or whether a tooth beneath is the true source.
About this treatmentDental condition · Wimpole Street, Marylebone
Swollen gums: reading the pattern, from plaque to pregnancy to infection
Healthy gum tissue is pale pink, firm and sits snugly against each tooth with a knife-edge margin. When it swells, the margin rounds off, the tissue turns darker and glossy, and brushing produces blood or a dull ache. The important question is not whether the gums are swollen but where. Puffiness across the whole mouth almost always reflects plaque sitting at the gumline for too long, sometimes amplified by hormones or a medicine. Swelling confined to one tooth is a different matter, pointing towards trapped food, a pocket that has become infected or a nerve that has died inside the tooth beneath. A lump that has grown steadily over weeks without pain is another category again. Our Wimpole Street dentists and hygienists work through that pattern systematically: the distribution, how long it has been there, what else is going on in your health, and what the X-ray shows beneath the surface.
Recognising it
How it usually feels
Gum margins that look rounded, shiny and darker red
Inflammation dilating the small vessels in the tissue; the classic look of gingivitis.
Bleeding on brushing, flossing or eating crusty food
Swollen tissue is fragile and bleeds with minimal contact.
Tenderness or a feeling of pressure between two teeth
Often a food packing problem or a pocket beginning to fill.
A soft, dome-shaped swelling beside one tooth
Suggests a periodontal or root abscess; may drain a salty fluid.
Gum that has overgrown and partly covers the teeth
Seen with certain medicines, in pregnancy, or with long-standing plaque under braces.
A firm lump that has grown slowly without pain
Usually a benign fibrous overgrowth, but always examined and sometimes biopsied.
Behind the symptoms
What's going on
- 01
Plaque left at the gumline
Bacterial film that is not removed within a day or two triggers an immune response in the gum beside it. The tissue swells to bring more defensive cells to the area. Remove the plaque thoroughly for a week and the swelling subsides; leave it, and the inflammation can progress to bone loss.
- 02
Hormonal changes
Pregnancy, puberty and, for some women, the days before a period alter how gum tissue responds to plaque, so the same amount of bacteria causes far more swelling. Pregnancy gingivitis peaks around the second trimester, and occasionally a localised “pregnancy epulis” lump develops and then shrinks after the birth.
- 03
Medicines
Some blood pressure tablets (calcium channel blockers such as amlodipine), the anti-epileptic phenytoin and the immunosuppressant ciclosporin can cause the gums to enlarge. Meticulous hygiene reduces it, and your GP may be able to substitute the drug.
- 04
Something trapped or an appliance that irritates
A popcorn husk, a fish bone or a piece of meat wedged below the gum produces rapid, localised swelling. Orthodontic brackets, a rough filling edge or an ill-fitting crown margin harbour plaque that a toothbrush cannot clear, and the gum beside them stays inflamed until the cause is corrected.
- 05
Abscess from the gum or the tooth
A deep periodontal pocket can block and fill with pus, or infection from a dead nerve can track up and burst through the gum near the root. Both produce a raised swelling on the gum beside one tooth, and the tooth often feels loose or tender.
- 06
Less common causes
Vitamin C deficiency, some blood disorders, and oral manifestations of conditions such as Crohn’s disease can present as swollen or granular gums. A swelling that does not fit the usual plaque pattern, or that persists despite excellent cleaning, is investigated further and may be referred.
Before your appointment
What you can do today
- Do not stop brushing swollen gums because they bleed; gentle, thorough brushing twice a day is what makes the bleeding stop.
- Clean between every tooth once a day with floss or interdental brushes of the right size, angling slightly under the gum.
- Use a soft or electric brush with a small head so you can reach the back teeth without scrubbing.
- Rinse with warm salt water two or three times a day for a week if a single area is sore.
- If something feels wedged between teeth, floss it out gently; do not dig with a pin or toothpick.
- Check the list of medicines you take against the ones known to enlarge gums and mention any match at your visit.
These are holding measures, not a substitute for an examination. Use any pain relief exactly as directed on the pack and check with a pharmacist if you take other medicines.
In the chair
How we treat it at Wimpole Street
Professional cleaning
A hygiene appointment removes the hardened deposits that home cleaning cannot, and Airflow polishing clears biofilm from below the gumline and around appliances. Most generalised swelling improves noticeably within two weeks.
About this treatmentPeriodontal treatment
Where pockets are deep and bone has been lost, roots are cleaned under local anaesthetic across one or more visits, then reassessed at three months.
About this treatmentCorrecting the plaque trap
A ledge on a filling is polished away, an overhanging crown margin is remade, or a rough surface is smoothed so that the gum can heal against a clean edge.
About this treatmentDraining an abscess
A gum abscess is drained and cleaned at the emergency visit; where the source is a dead nerve, root canal treatment or extraction follows.
About this treatmentGum recontouring
Fibrous overgrowth that remains once inflammation has resolved can be trimmed and reshaped, which also removes the ledges where plaque re-accumulates.
About this treatmentFees
Costs to expect
A full examination with periodontal charting at Wimpole Street is expected to be £95. A hygiene appointment is £89, or £142 with Airflow, and generalised gum swelling from plaque usually needs one or two visits followed by a routine schedule.
Where charting shows pockets and bone loss, a course of periodontal treatment is from £850. Emergency drainage of a gum abscess is around £95 for the visit, with any root canal or extraction fee added if the tooth is the source. Replacing a filling with an overhanging edge is from £185. Gum recontouring is quoted after examination.
Figures are indicative prices for Wimpole Street and are confirmed in a written plan once a dentist has examined you. Fees match our South Kensington and St Paul's clinics.
Don't wait if
When to see a dentist
- Gums have been swollen and bleeding for longer than two weeks despite good brushing.
- The swelling is confined to one tooth, is painful, or the tooth feels loose.
- A lump on the gum is enlarging, discharging or has been present for more than three weeks.
- You are pregnant and your gums have become sore and swollen.
- You take a medicine known to cause gum overgrowth and the tissue is starting to cover your teeth.
- Swelling has spread from the gum into the cheek or jaw, or you feel unwell with it.
FAQ
Common questions
Raised progesterone increases blood flow to gum tissue and changes its response to bacteria, so plaque that would once have caused mild redness now produces marked swelling. It does not damage the baby, but gum disease in pregnancy is worth controlling. Hygiene visits are safe throughout, and the tissue usually calms down after delivery.
Nearly always they reflect plaque, hormones or a local irritant. Rarely, gums that are swollen, bleed unusually easily and look pale or purplish can be an early sign of a blood disorder, and granular, cobblestone gums can accompany bowel disease. If the pattern does not fit and does not respond to cleaning, we arrange blood tests through your GP or a specialist opinion.
It can be. A crown margin that sits below the gum, has an overhang or has developed a gap traps plaque that no brush reaches, and the gum beside it stays inflamed. Sometimes the tooth under the crown has died and the swelling is an abscess draining through the gum. An X-ray and a probe around the margin tell us which, and the fix is different for each.
If it is plaque-driven and you improve your cleaning, yes, typically within one to two weeks. If it is caused by a trapped object, an abscess or a rough restoration, it will not settle until the cause is removed. A swelling that persists beyond a fortnight of good brushing needs to be looked at.
Marylebone, W1
Wimpole Street opens 1 October 2026
Leave your details and we will be in touch when the Marylebone diary opens. If the problem cannot wait, the same clinicians are already seeing patients in South Kensington and at St Paul's.
Related conditions
Opening 1 October 2026
Wimpole Street is not yet seeing patients. Until then, please book or call our South Kensington clinic on 020 7183 2362 or our St Paul's clinic on 020 7183 3709. Questions about the new clinic: wimpolestreet@md.co.uk.
Until we open
Need an appointment before 1 October 2026?
The same clinical team already works from two other Medical & Dental clinics. Book at either one now and, if you prefer, move your ongoing care to Wimpole Street once the doors open.
South Kensington
- 20 Old Brompton Road, London SW7 3DL
- Open seven days a week
- 020 7183 2362
St Paul's, City of London
- 5 Ave Maria Lane, London EC4M 7AQ
- Open Monday to Friday
- 020 7183 3709
