Tingling is a nerve being squeezed, starved of blood, or irritated. The familiar version — a foot gone to sleep — resolves in a minute once the pressure is off. The version worth understanding is the one that comes without pressure, or stays after it.
What it feels like from inside
Fizzing, buzzing, numbness, a sock-like dullness on the feet, fingers that feel thick in the morning, a hand that drops things. It is often worse at night or first thing.
The common patterns and what they usually mean
Thumb, index and middle finger, worse at night: the wrist nerve, very common and very treatable. Both feet, creeping up slowly: often the small nerves, linked to blood sugar, alcohol or vitamin levels. One arm or one leg, sudden: a different category altogether.
The ordinary explanations
Diabetes and pre-diabetes, low vitamin B12, alcohol, an underactive thyroid, some chemotherapy and other medicines, and repetitive use of the hands. Several of these are found with a single set of blood tests.
How to observe it usefully
Where exactly, both sides or one, when it started, what makes it better or worse, and whether there is weakness alongside. A rough sketch of the affected area on a hand or foot outline is genuinely helpful.
What to raise, and what not to wait on
Worth mentioning at a routine appointment: tingling that recurs in the same place for more than a few weeks, or numbness in the feet. Worth raising immediately: sudden numbness on one side, especially with weakness, facial droop or trouble speaking — that is an emergency, not an appointment.