The short answer
Steam, saline rinses and sitting upright. Decongestant sprays work but must not be used beyond about a week or the congestion comes back worse.
- Steam from a bowl of hot water or a hot shower thins the mucus. It is the oldest remedy here and it does help, if only briefly.
- Saline spray or rinse, which is cheap and can be used as often as you like.
- Sit and sleep propped up, which makes a noticeable difference overnight.
- Drink plenty, which keeps secretions thinner.
What will ruin it
Decongestant nasal sprays cause rebound congestion if used for more than about five to seven days. The nose becomes dependent on them and the blockage returns worse than it started. Saline has no such limit.
Why it works
Congestion is swollen blood vessels in the nasal lining as much as it is mucus. Decongestants constrict those vessels, and prolonged use makes them dilate harder when the drug wears off.
This is general information, not medical advice, and it does not replace a GP, a pharmacist or NHS 111. Call 999 in an emergency. Full disclaimer.