Hematoma endoscopic forehead lift numbness left side scalp.

At one month post-op, I would anticipate you have had some improvement. There may not be much to do but wait at this stage. Without an exam, it is hard to tell you what is going on. Permanent nerve damage from this would be rare. I would discuss your concerns with your doctor and if things are getting better just be patient as most minor issues resolve on their own. 

Hematoma after endoscopic brow lift is an uncommon complication.  After a few weeks, the blood clot becomes more liquid-like, and it is easily aspirated by placing a needle.  There is not much benefit to try to remove the hematoma at this point.  Nerve damage from the hematoma causing pressure to the nerve is a rare event, and even so, the numbness should subside in 2-3 weeks.  If persists, the nerve damage may not be from pressure of hematoma, but rather mechanical injury to the nerve.  Discuss these issues with your surgeon.Best,Alex Kim, MD