Which statement correctly differentiates serous, serosanguineous, sanguineous, and purulent drainage?

Which statement correctly differentiates serous, serosanguineous, sanguineous, and purulent drainage?

• A. Serous drainage is thick and opaque.
• B. Serosanguineous drainage is transparent and colorless.
• C. Serous drainage is clear and watery; serosanguineous drainage is pale pink; sanguineous drainage is bright red; purulent drainage is thick, opaque, often yellow/green.
• D. Purulent drainage is thin and watery.

Answer: (C)

Understanding drainage types helps you assess wound healing and possible infection. Serous drainage is a clear, watery fluid that comes from plasma. Serosanguineous drainage mixes serum with a small amount of blood, so it looks pale pink. Sanguineous drainage is predominantly blood, appearing bright red when fresh. Purulent drainage contains pus, making it thick and opaque, often yellow or green because of white blood cells and bacteria. The correct statement aligns with these descriptions: serous is clear and watery, serosanguineous is pale pink, sanguineous is bright red, and purulent is thick, opaque, often yellow/green. The other options misstate one or more characteristics—for example, serous is not thick and opaque, serosanguineous is not colorless, and purulent is not thin and watery.