I noticed a slight redness on my penis head. What could it be?

Hi,

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Thanks for the query. I can understand your concern. According to your statement, you suffer from the penis head's redness with urethra and soreness during active or sweating. According to the pictures (attachment removed to protect patient identity) provided here, you may suffer from balanitis, which may be urethritis. Balanitis is the inflammation of the glans penis or head of the penis. Inflammation of the urethra is known as urethritis. There are many triggering factors for developing balanitis, like personal unhygienic conditions, not washing and drying the head of the penis, partner's chlamydial infections, allergens, and irritants minor trauma, any infections caused by yeast, bacterial or viral, etc. You can undergo some investigations like urethral swab for C/S (culture and sensitivity), urine R/M/E (routine and microscopy), C/S, a biopsy from the lesions, etc. The exact underlying causes for your balanitis exclude other causes like chlamydial urethritis and then treat them accordingly. Take care. I hope I have answered your question. In case of any further query, ask me.