Hand Therapist Nigel Chua 
Yes. Any bite that breaks the skin of the hand needs the ER or urgent care today, especially a cat puncture or a split over a knuckle from a tooth. Those two seal bacteria into joints and tendons, and can turn into an infected joint overnight.
Numb hands on the bike are a nerve squashed at the wrist: ring and little finger is the ulnar nerve (handlebar palsy), thumb to middle finger is carpal tunnel. Change hand position every 10 to 15 minutes, get weight off your hands, and treat numbness that lingers after the ride as a deadline.
A hook of hamate fracture causes deep heel-of-palm pain on the little-finger side after a golf, bat or racquet impact, and routine X-rays often miss it. A CT settles it; most late-found cases do well with removal of the hook and a return to sport around 6 to 8 weeks.
Most A2 pulley injuries heal without surgery: about 6 weeks for a strain, 3 months to full crimping for a partial tear, nearer 6 months after a complete rupture. Visible bowstringing needs imaging.
A soft lump on the point of the elbow is usually olecranon bursitis and settles in 2 to 6 weeks once you stop leaning on it. Hot, red, painful, or a break in the skin means infection until proven otherwise: get seen today.
Most extensor tendon repairs take about 12 weeks: 4 to 6 weeks splinted, light use from weeks 6 to 8, full use around week 12. The real risk is a quiet lag, a finger that stops straightening all the way. Here’s the weekly check that catches it.
Needle release recovery takes days; open Dupuytren’s surgery takes about 3 months, with a night splint and hand therapy. Neither cures the disease, and the middle finger joint decides your result more than the operation does.
A scapholunate ligament tear often follows a fall, shows a normal X-ray and gets called a sprain. Back-of-wrist pain, a click and weakness still there at 6 weeks need proper imaging: six weeks buys a repair, six months a reconstruction, six years a fusion.
Guyon’s canal syndrome is the ulnar nerve squeezed at the wrist: numb ring and little fingers with a normal back of the hand. Pressure cases usually settle in 6 to 12 weeks once the load comes off; a cyst or hamate fracture needs finding and usually surgery.
Rheumatoid arthritis in the hands shows up as morning stiffness over an hour, soft swelling of the big knuckles, middle joints and wrists on both sides, and feeling unwell. Early treatment protects the joints; late treatment can’t rebuild them.