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 for:
Severe or rapidly worsening difficulty breathing
More than a few streaks or spots of coughed-up blood
Coughing blood with chest pain, faintness, or a very fast heartbeat
Sudden chest pain or collapse
A new seizure, severe confusion, or sudden weakness on one side
And for anyone, someone who:
is struggling to breathe, gasping, choking, or cannot get words out
Other emergency signs, for anyone
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 if you cough up any blood, even small streaks, or develop a significant new breathing problem.
During treatment, follow the urgent-contact instructions provided by the cancer team.
Fever, uncontrolled vomiting, sudden breathlessness, or marked weakness may need prompt assessment, especially when treatment can lower infection-fighting blood cells.
3
Does any of this apply?
Book an appointment
Arrange a routine medical appointment if you have a cough that lasts, a long-term cough that changes, unexplained weight loss, repeated chest infections, ongoing hoarseness, chest discomfort, or increasing breathlessness.
These symptoms are often caused by something other than cancer, but they should be assessed.
And for anyone, someone who:
has noticed a lump, a mole that has changed, or unexplained weight loss
Every sign above is quoted from the sofidex article on Lung cancer. If you are not sure, err upward — it is always reasonable to be checked.