Yes, black mold in the bathroom is dangerous, as it thrives in damp environments and can release harmful spores that may cause respiratory issues, allergies, and skin irritation. Common signs include dark spots on walls, a musty odor, and persistent humidity. If left untreated, it can spread and pose serious health risks, especially to those with asthma or weakened immune systems. To prevent and remove black mold, improve ventilation, fix leaks, and clean affected areas with mold-killing solutions like vinegar or hydrogen peroxide. In severe cases, professional mold remediation may be necessary.