You most definitely need to see a doctor for diagnosis and treatment.
Your symptoms suggest either a ligament tear, or Carpal tunnel
syndrome or tendinitis or bursitis.
It does seem your good deed led to this injury, but it's hard to be
100% certain if that was the direct cause, or if that was the straw
that broke the camel's back. The latter could be the case, especially
if you were, in fact, already in the process of developing something
like bursitis, tendinitis, or arthritis.
Your doctor can order an X-ray, and possibly other tests, in order to
make a precise diagnosis; then prescribe treatment, such as an
anti-inflammatory, vitamins (especially the B vitamins), rest, and a
splint for your thumb. (If it turns out to be Carpal tunnel, and is a
severe case, surgery may be recommended.)
Check your symptoms at these sites:
See the Pennsylvania State University's site on carpal tunnel:
"What are the symptoms?
Carpal Tunnel Syndrome usually causes numbness, tingling, and/or pain
in the affected hand(s). The numbness or tingling occurs in the
fingers innervated by the median nerve-the thumb, index, long, and
ring fingers. . . ."
Also see the MedLineplus Medical Encyclopedia (sponsored by the
National Institute Of Health) entry on "Numbness and Tingling":
There's a long list of possible causes of these symptoms, including a
link for Carpal tunnel, which brings up:
"Injury or trauma to the area, including (but not limited to)
repetitive movement of the wrists, can cause swelling of the tissues
and carpal tunnel syndrome. This type of injury may be caused by
sports . . . or occur during sewing, typing, driving, assembly-line
work, painting, writing, use of tools . . . or similar activities."
"Carpal Tunnel Syndrome," adapted from an Arthritis Foundation
brochure written by Charles H. McKenna, M.D., Lynn Yasuda, MSEd,
Jeffrey N. Katz, M.D., M.S., William Marras, Ph.D. and Lewis
Millender, M.D., is archived at the
University of Washington Department of Orthopaedics and Sports
"In most patients with CTS, the cause is not known. However, anything
that causes swelling on the tendons or produces repeated pressure on
the median nerve can lead to CTS or make it worse if the condition
already exists. Possible causes of pressure on the median nerve
include: Injuries, such as a blow to the wrist. This may break one or
more of the carpal bones and damage the median nerve."
Diagnostic tests for Carpal tunnel include:
"Tinel's sign test: The doctor will gently tap the front of the wrist.
If this causes tingling or pain in the hand or forearm, it may be due
Phalen's sign test: The doctor will ask the patient to bend your wrist
down as far as it will go and to hold this position from 15 seconds to
three minutes. If the patient feels tingling or pain, it may be due to
Nerve conduction velocity (NCV) study: This measures the nerve's
ability to send electrical impulses to the muscle. If the electrical
impulses are slowed down in the carpal tunnel, then CTS may be
X-rays of the hands and blood tests may be used to find out if there
are any other medical problems that are causing CTS.
Studies called Electromyogram and nerve conduction velocity or EMG/NCV
tests map the funciton [sic] of the nerve and help to confirm whether
the condition is mild or severe. This electrical study can also help
to identify other diseases or conditions that may mimic carpal tunnel
syndrome. Certain other conditions can place pressure on nerves at
different sites such as the neck and elbow."
I also checked your symptoms at WebMd.com:
My search there brought up this article "Finger, Hand, and Wrist
That same search at WebMd.com also brought up the article "Finger,
Hand, and Wrist Injuries":
Scroll down to "Sudden (acute) Injury" and click on the link "torn
thumb ligament" to bring up a pop-up box showing the kind of tear you
may have suffered.
Review tendinitis (inflamed tendon); bursitis (rupture of the fluid
sac near a bone or tendon); and De Quervain's tenosynovitis (swelling
of the tendon) symptoms at WebMD.com:
(Scroll about 1/3 of the way down the page to start checking
Call your doctor for an appointment. In the meantime, take an
anti-inflammatory, either aspirin or ibuprofen. (I've found that the
pain reliever Orudis is especially effective for this type of pain.)
As long as you're at the drugstore, you may want to buy a thumb
splint; keeping the thumb immobilized may help reduce the pain.
Please post a request for clarification if you have any trouble
navigating these links, or if any of the information I've given you
I hope you feel better soon.