Bleeding very heavily
This means heavy bleeding that is continuing despite attempts to stop it.
A severe injury
This includes deep wounds, or injuries caused by falls, assault or road traffic accidents and will require an immediate medical assessment.
The person you are enquiring about is unconscious having a seizure (fit)
Unconscious - Not awake and totally unaware of what is going on around you. As if you are asleep, but with no response if someone tries to wake you.
Seizure - Uncontrolled electrical activity in the brain, which can lead to loss of consciousness and/or loss of bladder and bowel control. Seizures are often known as fits.