People asking this usually want to know whether the amount is normal. The amount alone isn’t what matters most. Change is.
With an ischemic ulcer, more drainage than before, or drainage that is yellowish or cloudy, is one of the signs of infection that should prompt you to contact your provider. With a diabetic foot ulcer, extra drainage is a sign in the same way.
With surgical wounds, think about the dressing: you will want to change it sooner if it becomes wet or soaked with blood or other fluids. Contact your surgeon if the drainage coming from or around the incision increases or becomes thick, tan, green, yellow, or smells bad.
The dressing schedule matters too. If liquid leaks out of the dressing, or if the wound is much more painful than before without a clear reason, it’s strongly recommended that you contact your treating health care professional.
Drainage also has a purpose, which is easy to forget when there seems to be a lot of it. With wounds left open to heal, a dressing absorbs drainage and keeps the skin from closing over the wound before the tissue underneath fills in.
There’s no set amount that counts as too much. What matters is the direction things are going, so the question to ask is not “how much?” but “is it more than before?”