If you woke up with numbness in your left thumb, it could be due to various reasons. It is important to first check for signs of infection such as inflammation, redness, fever, or a general feeling of illness. If any of these symptoms are present, it is advised to consult a healthcare professional within 24 hours. If the numbness is a result of repetitive movements or unusual physical exertion, it may improve with the use of anti-inflammatory medication (like Advil), as long as you do not have any allergies or other health issues. Without these conditions, you can try gentle massages and applying heat for 10 to 15 minutes, 3 to 4 times a day to see if there is any improvement. If the numbness persists, worsens, or new symptoms develop, then it would be necessary to seek medical advice.