Actinic keratosis (AK) is a precancerous skin condition caused by excessive sun exposure. It typically presents as scaly or crusty patches on the skin. Red flags for AK include the presence of persistent red, scaly patches or spots that become thicker over time, an area of skin that itches, bleeds, or becomes tender, and any new skin growths or sores that fail to heal. Additionally, people with fair skin, blue or green eyes, and light or red hair are at an increased risk of developing AK. If any of these red flags are present, it is important to seek medical attention promptly to ensure early diagnosis and treatment.