Last updated: October 2026
Hives (urticaria) are raised, itchy welts that can appear anywhere on the body. Each one usually fades within a day, though new ones may appear elsewhere. Common triggers include allergies, infections, heat, pressure and stress, but often no cause is found. A pharmacist can advise on antihistamines. Call 999 if your lips, tongue or throat swell or breathing gets hard.
Below: what hives look like, causes, stress hives, how long they last, what helps and when it’s an emergency.
You’re not alone: the British Association of Dermatologists says up to 1 in 5 people get hives at some point in their lives. For most, it’s a short, harmless episode that settles within days.
What do hives look like?
Hives are also called urticaria, weals and nettle rash, as they look like nettle stings. The NHS describes them as raised bumps or patches in many shapes and sizes, which can itch, sting or burn.
- Raised welts. Each one is a smooth, puffy swelling, from a few millimetres across to the size of a hand. Some join together into larger patches or rings.
- A pale centre with a red edge. Doctors describe a central swelling (red or white) surrounded by a flare of redness.
- They move. A welt usually fades within 1 to 24 hours without a mark, while new ones appear elsewhere. This coming and going is the biggest clue.
- Anywhere on the body. They can stay in one area or spread across the body, including the face.
On white skin hives look pink or red. On brown or black skin the colour can be harder to see. Hives may look slightly lighter or darker than the surrounding skin, or the same colour, so the raised, puffy feel and the itch are the main clues.
A rash where each spot lasts longer than a day, hurts or leaves a bruise-like mark isn’t typical hives: see a GP.
What causes hives?
Hives happen when cells in the skin called mast cells release histamine and other chemicals. This makes tiny blood vessels leak fluid into the skin, causing swelling and itch. Many triggers aren’t allergies at all.
| Trigger | Examples | Good to know |
|---|---|---|
| Foods | Milk, eggs, peanuts, tree nuts, shellfish | With a true food allergy, hives usually appear within an hour of eating the food, not overnight |
| Medicines | Penicillin and some other antibiotics, aspirin, ibuprofen and other NSAIDs, codeine | Never stop a prescribed medicine without talking to your GP or pharmacist |
| Insect bites and stings | Wasp and bee stings | Can also trigger a serious allergic reaction in some people |
| Contact with something | Latex, certain plants, animals or chemicals | Hives appear where the skin touched it (contact urticaria) |
| Infections | Colds and other viral infections | A very common cause in children |
| Physical triggers | Cold water or wind, heat, sweating, pressure from tight clothing, scratching, sunlight (rare) | Known as inducible (physical) urticaria |
| Stress | Emotional stress, often with heat or exercise | Can trigger hives or make existing hives worse |
| No cause found | Hives that come out of nowhere | Very common, especially in long-lasting hives |
Physical hives come in several types. Cold urticaria flares after cold exposure, worth knowing before trying cold water swimming. With dermatographism, scratching raises itchy lines on the skin. Delayed pressure urticaria causes swelling after sustained pressure, such as sitting or a tight waistband.
If you also sneeze or get itchy eyes indoors, an allergy such as dust mite allergy may be part of the picture. Tests aren’t usually needed for a one-off bout, but your GP may consider them if hives keep coming back.
Acute vs chronic hives
Doctors split hives by how long they’ve lasted. The dividing line is 6 weeks.
| Acute urticaria | Chronic urticaria | |
|---|---|---|
| How long | Less than 6 weeks | 6 weeks or more, on most days |
| How common | About 1 in 5 people over a lifetime | About 1 in 50 people over a lifetime |
| Usual causes | Viral infections, foods, medicines, stings, or no clear cause | Usually no external cause found (chronic spontaneous urticaria), or physical triggers (chronic inducible urticaria) |
| Outlook | Normally clears by itself | Often lasts months to years, then settles |
Chronic spontaneous urticaria (CSU) means hives on most days for 6 weeks or more without an obvious trigger. It isn’t usually an allergy. In around 30 to 50% of cases there’s an autoimmune element: the immune system makes antibodies that switch on the skin’s own mast cells. It can run alongside thyroid problems, so mention any thyroid symptoms to your GP. See underactive thyroid symptoms for the signs to mention.
Heat, stress, NSAID painkillers and infections can all make CSU flare. Hives in general are most common between the ages of 20 and 40, and more common in women than men.
Hives from stress
Yes, stress can bring you out in hives. Your skin is closely wired into your stress response, and researchers describe a two-way link between stress, nerves and the immune cells in the skin that release histamine. The NHS lists emotional stress as a trigger, and it can make long-lasting hives worse.
The best-known type is cholinergic urticaria: itchy bumps that appear when your body warms up, whether from exercise, a hot shower or a strong emotion such as stress. A 2020 systematic review describes a close link between psychological stress and chronic hives, but found it’s still unclear whether stress starts the condition or mainly sets off flares in people already prone to it.
We cover stress hives in detail in our stress rash guide. See also stress symptoms, and for quick ways to settle your nervous system, how to calm down and box breathing.
A calming evening routine can help with stress. Our Magnesium Glycinate Sleep Complex is a caffeine-free evening drink, and magnesium contributes to normal psychological function and to the normal functioning of the nervous system. Our products aren’t a treatment for hives. They’re for adults only. We don’t recommend our products during pregnancy or breastfeeding, and if you take any medication, check with your GP or pharmacist first.
How long do hives last?
- Each welt: usually 1 to 24 hours before the skin returns to normal, leaving no mark.
- A bout of acute hives: often 24 to 48 hours, and by definition gone within 6 weeks. Most people only ever have one episode.
- Chronic hives: months or years. About half of people with chronic spontaneous urticaria go into remission somewhere between 6 months and 5 years, and around 1 in 5 still have it after 10 years.
Hives that keep coming back for more than 6 weeks need a GP review, even if each bout is short.
What helps hives
Mild hives often settle without any treatment. If the itch is bothering you:
- Ask a pharmacist about a non-drowsy antihistamine, such as cetirizine or loratadine. These are the main treatment for hives. Tell the pharmacist about any long-term condition or other medicines, and ask before giving them to a young child.
- Keep cool. Heat makes hives worse, so choose a cool shower and light layers over a hot bath.
- Wear loose, soft clothing. Tight waistbands, straps and itchy fabrics can set off pressure hives.
- Try not to scratch. Scratching and rubbing can raise new welts. A fragrance-free moisturiser helps if your skin is also dry; see dry skin.
- Cut back on alcohol during a flare, as it can make hives worse.
- Keep a symptom diary. Note the time, food, medicines, activity, temperature and stress. Patterns help find triggers, and GPs find diaries useful.
- Avoid triggers you’ve identified, from cold wind to a particular food.
If hives last longer than 6 weeks, a GP may suggest a daily antihistamine for several months, a different antihistamine or a menthol cream. Steroid tablets are sometimes used briefly for a severe flare. Higher antihistamine doses are only used under medical supervision, so don’t increase the dose yourself. If hives still aren’t controlled, a dermatologist or immunologist can offer specialist treatments such as omalizumab injections or ciclosporin.
Hives or something else?
The quickest test for hives is whether each mark moves on within a day. Here’s how hives compare with common lookalikes.
| Rash | What it looks like | How it differs from hives |
|---|---|---|
| Hives | Raised, puffy welts, often with a pale centre | Each welt fades within 24 hours and new ones appear elsewhere |
| Eczema | Dry, red, itchy patches | Patches stay for days or longer, with dry skin around them |
| Heat rash | Small spots 2 to 4mm across, prickly or itchy | Tiny spots rather than welts, after getting hot; clears in a few days |
| Insect bites | Small, itchy, swollen lumps, often in groups | Smaller and each one lasts longer than a day |
| Pityriasis rosea | One oval scaly “herald patch”, then smaller scaly spots on the chest and back | Scaly, stays put and lasts weeks to months |
| Chickenpox | Spots that turn into fluid-filled blisters, then scabs | Spots blister and then scab; contagious |
| Urticarial vasculitis (rare) | Hive-like welts | Last over 24 hours, hurt, and leave a bruise-like mark; see a GP |
| Meningitis rash | Spots or a rash with feeling very unwell | Doesn’t fade when you press a clear glass on it; call 999 |
The glass test: press the side of a clear glass firmly against the rash. If it doesn’t fade, call 999 or go to A&E. On darker skin, check paler areas such as the palms and soles. Not everyone with meningitis gets a rash, so don’t wait for one if you’re worried.
Long-lasting, scaly patches are more like psoriasis, and persistent redness across the cheeks and nose may be rosacea.
When hives are an emergency
Most hives are harmless, but hives can be the first sign of anaphylaxis, a severe allergic reaction, or come with angioedema, a deeper swelling under the skin. About half of people with chronic hives also get angioedema at times. It usually affects the lips, eyelids, tongue, hands or feet, and it’s more often painful or tight than itchy.
Call 999 if you or someone else has hives and:
- the lips, mouth, throat or tongue suddenly swell
- breathing is very fast or difficult, or there’s wheezing
- the throat feels tight, the voice is hoarse or swallowing is hard
- the skin, lips or tongue turn blue, grey or pale (on brown or black skin this may be easier to see on the palms or soles)
- they suddenly feel very confused, drowsy, dizzy or faint, or collapse
- a child is limp, floppy or not responding normally
What to do while you wait:
- Use an adrenaline auto-injector (such as an EpiPen) if one has been prescribed. The instructions are on the side.
- Call 999 and say you think it’s anaphylaxis.
- Lie down and raise the legs. If breathing is difficult, sit up slowly instead.
- If there’s an insect sting still in the skin, remove it.
- If symptoms haven’t improved after 5 minutes, use a second auto-injector if there is one.
- Don’t stand up or walk, even if you start to feel better.
Don’t drive yourself to hospital. Swelling of the lips, face or eyes without hives can also be caused by some blood pressure medicines (ACE inhibitors), so mention any medicines you take.
When to see a pharmacist or GP
Start with a pharmacist for antihistamine advice. Get an urgent GP appointment or call NHS 111 if:
- your hives haven’t improved after 2 days
- the rash is spreading
- hives keep coming back, which may point to an allergy
- you have a high temperature and feel unwell
- you have swelling under the skin as well as hives
- you’re worried about your child’s hives
See your GP routinely if hives have come and gone for more than 6 weeks, are affecting your sleep or mood, or each welt lasts more than a day or leaves a mark.
A painful, blistering rash in a band on one side of the body is more likely to be shingles: see our shingles guide.
FAQs
What causes hives?
Hives happen when mast cells in the skin release histamine. Triggers include foods, medicines such as NSAIDs or antibiotics, insect stings, viral infections, heat, cold, pressure and stress. Often no cause is found.
What does hives look like?
Raised, itchy welts, often with a pale centre and red edge, that change shape and move within hours. On brown or black skin they may be the same colour as the skin, so the raised feel and itch are the main clues.
Can stress cause hives?
Yes. Emotional stress is a recognised trigger and can make long-lasting hives flare. Keeping cool and antihistamines from a pharmacist can help.
How long do hives last?
Each welt usually fades within 24 hours, and a bout often clears in a day or two. Hives lasting 6 weeks or more are called chronic and can last months or years.
Are hives contagious?
No. Hives are a reaction inside your own skin, so you can’t catch them from someone or pass them on. If a virus triggered your hives, though, the virus itself may be catching.
When are hives serious?
Call 999 if hives come with swelling of the lips, tongue or throat, difficulty breathing or swallowing, or feeling faint. See a GP if hives haven’t improved after 2 days or keep coming back.
Sources
- NHS. Hives.
- NICE Clinical Knowledge Summaries. Urticaria (revised January 2026).
- British Association of Dermatologists. Urticaria and angioedema patient information leaflet.
- nidirect (NHS Northern Ireland). Urticaria (hives).
- NHS. Anaphylaxis and Angioedema.
- NHS. Meningitis, Pityriasis rosea, Heat rash, Insect bites and stings and Chickenpox.
- Zuberbier T et al (2022). The international EAACI/GA²LEN/EuroGuiDerm/APAAACI guideline for the definition, classification, diagnosis, and management of urticaria. Allergy.
- Konstantinou GN, Konstantinou GN (2020). Psychological stress and chronic urticaria: a neuro-immuno-cutaneous crosstalk. A systematic review of the existing evidence. Clinical Therapeutics.
This guide is general information, not medical advice. Our products aren’t a treatment for hives. Evopure makes the Magnesium Glycinate Sleep Complex.
