Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Seek emergency care for severe trouble breathing, fainting, new chest pressure or pain, a rapid or irregular heartbeat with weakness or breathlessness, or sudden inability to move with dark urine.
A personal emergency plan can list the diagnosis, medicines, heart and lung findings, anesthesia precautions, and specialist contact details.
Keeping a copy available may help during unexpected care.
Dark urine after exercise or illness needs prompt same-day medical advice.
These symptoms do not always indicate a complication of Becker muscular dystrophy, but they require urgent evaluation.
Routine follow-up should include review of strength, mobility, falls, pain, joint movement, equipment needs, and participation in daily activities.
Heart evaluations are needed regularly, including for many female carriers.
The care team may also monitor breathing, sleep, bone health, nutrition, and emotional well-being.
The article also says
Contact the usual care team soon if there is a clear decline in walking, new swelling in the legs, increasing shortness of breath, repeated falls, morning headaches, sleep-related breathing symptoms, or new difficulty swallowing.
Every sign above is quoted from the sofidex article on Becker muscular dystrophy. If you are not sure, err upward — it is always reasonable to be checked.