Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
These concerns usually need timely outpatient review rather than emergency care.
Emergency services are appropriate for a seizure, breathing difficulty, unresponsiveness, or another immediately life-threatening symptom.
Seek urgent assessment if an infant has poor feeding, repeated vomiting, jaundice, marked sleepiness, fever, abnormal bleeding, or other signs of serious illness.
Routine follow-up may review growth, nutrition, dietary galactose exposure, development, school progress, movement symptoms, emotional well-being, and bone health.
The article also says
Ongoing care is usually coordinated through a metabolic genetics clinic.
Children may benefit from formal speech, language, developmental, and learning assessments even when early milestones seem typical.
Speech therapy, occupational therapy, physical therapy, and educational accommodations can be added according to the child's needs.
Adolescents should receive age-appropriate education about managing their own diet and medical care.
Girls may need monitoring of puberty, menstrual cycles, and ovarian function.
Adults may need continued support related to nutrition, bone health, mental health, fertility, education, or employment.
Contact the regular care team if there are new problems with growth, diet, speech, learning, balance, tremor, mood, puberty, or menstrual periods.
Every sign above is quoted from the sofidex article on Classic galactosemia. If you are not sure, err upward — it is always reasonable to be checked.