Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
1
Is any of this happening now?
Call 911
Call emergency services now if you or someone else has:
Severe difficulty breathing
New confusion, extreme drowsiness, or loss of consciousness
Fainting with pale, cold, or clammy skin
Chest pain or signs of a heart attack
A seizure lasting several minutes or repeated seizures
Suspected carbon monoxide, cyanide, or medicine poisoning
Signs of shock, such as profound weakness, very little urine, or collapse
If carbon monoxide exposure is possible, leave the area for fresh air without delaying and call emergency services.
Do not re-enter an unsafe building.
A mildly raised lactate found during testing does not always mean there is an emergency, but it must be interpreted in its clinical setting.
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
Someone who has chest pain, tightness or pressure lasting more than a few minutes
Someone who has sudden weakness or drooping on one side of the face or body, slurred speech, or sudden confusion
Someone who is unconscious, or cannot be woken
Someone who is bleeding heavily and it will not stop with firm pressure
Someone who has had a seizure that will not stop, or does not wake up afterwards
Someone who has lips or skin that look pale, blue, grey or blotchy
Someone who you believe has taken an overdose or swallowed something poisonous
2
Is any of this happening?
Be seen today
Seek urgent same-day medical advice for persistent vomiting or diarrhoea, worsening dehydration, rapid breathing, unusual weakness, or reduced urine output.
This is especially important if you take metformin or have kidney, liver, heart, or lung disease.
3
Does any of this apply?
Book an appointment
Routine follow-up is appropriate after recovery to review test results, medicines, and the underlying cause.
Every sign above is quoted from the sofidex article on Lactic acidosis. If you are not sure, err upward — it is always reasonable to be checked.