Red blood streaks at the root of the thigh may be related to trauma, atrophic lines, lymphangitis and other diseases. 1. Trauma: If the thigh root is subjected to external blows, collisions and other injuries, it may cause the local subcutaneous capillaries to be damaged and ruptured, thus triggering the emergence of localized red blood streaks. 2. Atrophic lines: its etiology may be related to heredity, pregnancy influence, obesity and other factors. Patients will appear skin erythema, such as dots, spots, starbursts, etc., and some patients will appear red blood stripes on the thigh roots. 3. Lymphangitis: the cause of most of its pathogens through the skin mucous membrane wounds, surgical incisions and other tissues lymphatic interstitial infection of lymphatic vessels leading to the spread of infection along the lymphatic vessels, the disease is most common in the limbs, the main manifestation of the wounds near the emergence of one or more red lines. There are many reasons for the red streaks of blood at the base of the thighs, and patients are advised to seek medical examination to clarify the cause.