When someone with an infection such as pneumonia or a urinary tract infection suddenly breathes fast, slurs their speech and turns blotchy, it may be sepsis. The UK National Health Service (NHS) describes sepsis as a serious reaction to an infection that can be life-threatening, saying it usually develops quickly over a few hours and, untreated, can turn into septic shock, which you can die from. Here are the NHS symptoms in children and adults, when to call 999, hospital treatment, recovery and post-sepsis syndrome, set out as written.
1. Sepsis usually develops over a few hours — if you suspect it, call 999 or go to A&E (119 in Korea, our note).
2. A child under 5 who hasn’t peed for 12 hours, a rash that doesn’t fade, very fast breathing: emergency signs.
3. After recovery, post-sepsis syndrome often lasts 6 to 18 months — tiredness, memory problems and more.
Symptoms — NHS
The NHS says sepsis usually develops quickly over a few hours. Children and adults are set out separately.
| Who | Symptoms the NHS lists | Worth noting (ours) |
|---|---|---|
| Babies and children | Difficulty breathing or breathing very fast, a fit (seizure), a high or low temperature (very hot or cold to touch) | — |
| Babies and children | Blue, grey, pale or blotchy skin, lips or tongue; a rash that does not fade when pressed | Rare in sepsis; may be meningitis, the page says |
| Babies and children | Sleepier than normal or hard to wake; no pee in 12 hours under 5, or all day at 5 and over | Check a baby’s nappy |
| Under 5 | Not interested in feeding, or keeps vomiting | — |
| Adults | Confusion or slurred speech, uncontrollable shivering, muscle pain, difficulty breathing | — |
| Adults | Blue, pale, grey or blotchy skin, lips or tongue; a high or low temperature | High temperature is less common in older adults |
| Adults | No pee all day, or very little in the past 18 hours | — |
On black or brown skin, colour changes may be easier to see on the palms of the hands or soles of the feet. Symptoms are harder to notice in babies and young children, people with dementia, people with a learning disability and people who have difficulty communicating. The NHS says trust your instincts: someone with sepsis might not have every symptom, so get help immediately if you think something is seriously wrong.
Call 999 or go to A&E — NHS
| Who | Call 999 or go to A&E if | Worth noting (ours) |
|---|---|---|
| Baby or child under 5 | Breathing very fast or with difficulty — grunting, tummy sucking under the ribcage | 119 in Korea |
| Baby or child under 5 | Blue, grey, pale or blotchy skin, lips or tongue; a rash that does not fade when pressed | — |
| Baby or child under 5 | Very high temperature — 38C or more under 3 months, 39C or more at 3 to 6 months | The threshold depends on age |
| Baby or child under 5 | Very low temperature — less than 36C, cold to touch or shivery | — |
| Baby or child under 5 | Weak, high-pitched or continuous cry; not responding as normal, not feeding, hard to wake; no pee for 12 hours | — |
| Adult or child 5 and over | Breathing very fast; confused, slurred speech or not making sense | — |
| Adult or child 5 and over | Blue, pale or blotchy skin; very high or low temperature or shivery; a rash that doesn’t fade | — |
| Anyone | Symptoms you’re worried might be sepsis | — |
Do not drive to A&E: ask someone to drive you or call 999 for an ambulance, and bring any medicines you take. In Korea, calling 119 is the equivalent (our note).
Causes and who is at risk — NHS
The exact cause isn’t known; it’s thought the immune system overreacts to an infection and starts to damage the body’s organs. Any infection can lead to sepsis, but bacterial infections are the most common cause.
| Type | What the NHS says | Worth noting (ours) |
|---|---|---|
| Common causes | Chest infections (pneumonia), UTIs, abdominal infections such as appendicitis, skin infections such as cellulitis or infected wounds | Pneumonia is covered below |
| Age | Babies under 12 months; people over 75 | — |
| Pregnancy | Pregnant, or given birth, had an abortion or a miscarriage in the past 6 weeks | — |
| Weak immunity | HIV or sickle cell disease, chemotherapy, corticosteroids or immunosuppressants | — |
| Wounds, tubes | A burn, cut or wound, cellulitis; a urinary catheter | — |
| Other | Injecting illegal drugs; misusing alcohol | — |
Pneumonia symptoms and treatment are in pneumonia.
Treatment — NHS
Sepsis is treated in hospital, depending on age and how unwell you are. You may be given a general antibiotic first and a more specific one once the cause is confirmed, oxygen to help breathing, and fluids into a vein. Some people need a specialist care unit for close monitoring.
Recovering — NHS
| Type | What the NHS says | Worth noting (ours) |
|---|---|---|
| Be patient | Recovery can take weeks or months; don’t rush it | — |
| Sleep | Adults usually need 7 to 9 hours a night | — |
| Eating | A balanced diet; smaller meals more often if appetite is low | — |
| Exercise | Regularly, but start slowly and build up | — |
| Diary | Track sleep, exercise and symptoms | — |
| Talking | Talk to a partner or friend; in the UK a sepsis charity has support nurses | — |
Complications — post-sepsis syndrome (NHS)
After sepsis you may get post-sepsis syndrome (PSS): feeling very tired, hearing loss, nerve damage causing numbness or weakness in hands and feet, problems with organs such as the heart, kidneys and lungs, depression, anxiety and loss of confidence, and cognitive problems such as memory loss and poor concentration. It affects everyone differently, often lasting 6 to 18 months, sometimes much longer. Treatment targets the symptoms and may include physiotherapy, counselling and extra support.
Damage to the immune system can make other infections more likely. If you or your child had sepsis in the past 12 months and have signs of an infection, such as a very high temperature or feeling hot, cold or shivery, call NHS 111. In Korea, tell the hospital that treated you and get seen quickly (our note).
Checklist
- ☐ Fast breathing, confusion or slurred speech during an infection?
- ☐ Blue or blotchy skin or lips; a rash that doesn’t fade
- ☐ Pee — 12 hours for under 5s; very little in 18 hours for adults
- ☐ 38C or more under 3 months, 39C or more at 3 to 6 months, under 36C
- ☐ Don’t drive yourself; bring your medicines
- ☐ Infection signs within 12 months of sepsis: get seen quickly
Questions that remain
No fever means no sepsis?
No. The NHS says the temperature can be high or low, and a high temperature is less common in older adults. Not every symptom appears, so trust your instincts.
Can sepsis be prevented?
The page has no prevention section. Since the common causes are pneumonia, UTIs and skin infections, treating those early is the link we read from it (our note).
Sources
- NHS — Sepsis — source (page shows: reviewed 14 May 2026, next review due 14 May 2029; checked 27 October 2026). Symptoms in children and adults, people in whom it’s harder to notice, 999 and A&E criteria (under 5; 5 and over and adults), treatment, recovery, post-sepsis syndrome, repeat infections and 111, causes, risk factors.
- Not read. The UK sepsis charity pages, the videos, Korean sepsis guidance.
- What we added. The “worth noting” column and the Korean care gloss.
Where to check further
- Emergency department (119 in Korea) — straight away if you suspect it.
- The hospital that treated you — after-effects and new infections.
Written on 27 October 2026. The content is from the NHS; the glosses are ours.
