These events are episodic, and when the episode subsides or the area is warmed, the blood flow returns, and the skin color first turns red (rubor), and then back to normal, often accompanied by swelling, tingling, and a painful "pins and needles" sensation. All three color changes are observed in classic Raynaud's. However, not all patients see all of the aforementioned color changes in all episodes, especially in milder cases of the condition. The red flush is due to reactive hyperemia of the areas deprived of blood flow.