Quick answer
What is rsv (respiratory syncytial virus)?
RSV is a common respiratory virus that usually causes cold-like symptoms. In babies, especially those under 6 months, it can cause bronchiolitis with breathlessness and poor feeding. Most infections are mild and get better within 1 to 2 weeks, but seek urgent help if a baby is struggling to breathe or not feeding.
What is RSV?
Respiratory syncytial virus (RSV) is one of the most common viruses affecting the lungs and airways. Almost all children have been infected by age two. In most people it causes a mild cold, but in young babies — particularly under six months — it can cause bronchiolitis, a condition that makes breathing and feeding harder.
RSV circulates every winter and is a major reason babies are admitted to hospital in the colder months.
Symptoms
RSV symptoms depend on age and general health:
In babies and young children:
- runny or blocked nose
- cough
- fever
- reduced feeding or drinking
- breathlessness or wheezing
- irritability and tiredness
In older children and adults:
- cold-like symptoms — blocked nose, cough, sore throat
- sometimes a mild fever and headache
Most infections improve within one to two weeks without specific treatment.
Bronchiolitis in babies
When RSV affects the small airways in babies, it can cause bronchiolitis. Warning signs include:
- fast or laboured breathing
- wheezing or a crackly sound when breathing
- difficulty feeding — taking less than half the usual amount
- fewer wet nappies
Most babies with bronchiolitis can be cared for at home, but some need hospital monitoring and support with feeding or oxygen.
How RSV spreads
RSV spreads through coughs, sneezes, and direct contact — similar to a cold. It survives on surfaces for several hours. Good hand hygiene and avoiding close contact with vulnerable babies when you have cold symptoms helps reduce spread.
Caring for a child at home
For mild RSV:
- offer fluids or feeds little and often
- keep the child upright if a blocked nose makes feeding difficult
- paracetamol or ibuprofen for fever, following age-appropriate dosing
- saline nose drops can help clear a blocked nose in babies
Do not smoke around children — it increases the severity of RSV.
RSV vaccination
The NHS now offers RSV vaccination to help protect those at highest risk, including older adults and pregnant women (from 28 weeks). Check current NHS eligibility — vaccination reduces serious illness but does not prevent all infections.
When to seek help
Trust your instincts with babies. Seek urgent help for struggling to breathe, blue lips, poor feeding, or a baby who is much more lethargic than usual.
Common questions
- What is RSV?
- Respiratory syncytial virus (RSV) is a common virus that infects the lungs and breathing passages. It causes colds in older children and adults, but can cause more significant breathing problems in young babies.
- What is bronchiolitis and how is it linked to RSV?
- Bronchiolitis is inflammation of the small airways in the lungs, most often caused by RSV in babies under 12 months. It causes cough, wheeze and breathlessness. Most babies recover at home, but some need hospital care.
- Is there a vaccine for RSV?
- Yes. The NHS offers RSV vaccination to people aged 75 to 79, and to pregnant women from 28 weeks to protect newborn babies. Eligibility may change — check current NHS guidance.
- How can I help a baby with RSV at home?
- Offer smaller, more frequent feeds, keep them upright where possible, and use paracetamol or ibuprofen for fever if age-appropriate. Do not smoke near the baby. Saline nose drops can help a blocked nose.
- Can adults get RSV?
- Yes. In healthy adults it usually causes a cold-like illness. Older adults and people with heart or lung disease may become more unwell and should seek advice if breathless.