Call 999 for help if you have any of these:

Signs of a heart attack (chest pain, pressure, heaviness, tightness or squeezing across the chest)
Signs of a stroke (face dropping on one side, cannot hold both arms up, difficulty speaking)
Severe difficulty breathing (not being able to get words out, choking or gasping)
Seizure (fit) (shaking or jerking because of a fit, unconscious or cannot be woken up)
Severe injuries (after a serious accident or assault)
Choking (on liquids or solids right now)
Sudden, rapid swelling (of the eyes, lips, mouth, throat or tongue)
Sudden confusion (delirium) (cannot be sure of your name or age)
Heavy bleeding (spraying, pouring or enough blood to make a puddle)
Your life is in danger (suicide attempt) (you have taken something or self-harmed, or may be about to do this)

See NHS advice on when to call 999 if you are unsure.