Hospital emergency rooms treat injured fingers all the time. Without treatment, a bad cut can lead to
permanent damage. But how should a person know when a bleeding cut is serious enough to require
medical attention?
      Here are some tips from Dr. Martin Brown, chairman of the department of emergency at Inova
Alexandria Hospital in Virginia. 
     1. Laceration (裂口)
     The medical term for a cut or tear in the skin is a laceration.   1   A long cut on a finger can likely be
treated without a visit to a doctor if the wound is not very deep. However, if you have a short but deep
laceration, you will need professional attention,
     2. Fingertips cut off
     Some injuries, like a fingertip that gets cut off, might even need surgery (外科手术) to repair.   2   
More often, cutting down the bone is what is done because reattaching a fingertip is often not successful.
     3. Bleeding 
       3    Small cuts usually produce what is known as venous (静脉的) bleeding. This means the blood
flows steadily from the injury. The bleeding will often stop when pressure is put on the wound. In most
cases holding direct pressure with a clean cloth for four to five minutes would do. But if a cut appears to
be pumping blood out with some force, this may be a sign of arterial (动脉的) bleeding.   4     
     Finally, always keep this in mind: even a cut that does not require medical attention must be kept clean
to prevent infection. Small cuts should be cleaned gently with clean water.   5    Then cover it with a clean,
dry bandage.