A lump in the underarm can be an infected hair follicle, hidradenitis, a cyst or an enlarged lymph node; it cannot be diagnosed safely from text alone. Do not squeeze it or start antibiotics without examination. I need to know its duration, pain, redness, discharge and whether it is growing.
Next Steps
Please arrange an in-person physician or surgeon review for examination; an ultrasound may be needed if the lump persists or is deep. You can book a consultation with me and share a clear photo if appropriate.
Health Tips
Seek urgent care if red