Can a blood clot on the hand close to the wrist area look like a lump and if it is a blood clot could it be dangerous?

Unlikely: It would be unlikely for a blood clot to show up as a cystic area. More likely a ganglionic cyst in the wrist area. Get eval to get the real and definitive diagnosis. Best wishes.

Blood clot: Concerning blood clots are usually those that occur in the deeper larger vessels. Superficial clots may cause dark-colored bumps on the skin but are usually benign. A lump around the wrist may be from a ganglionic cyst that occur on or around tendons/joints.