Originally Answered: help!i really need answers fast!?
Paresthesias of the hands and feet are common, transient symptoms of the related conditions of hyperventilation syndrome, often open mouth, and panic attacks.
Other common examples occur when sustained pressure has been applied over a nerve, inhibiting/stimulating its function. Removing the pressure will typically result in gradual relief of these paresthesias, often described as a "pins and needles" feeling.
Chronic paresthesia indicates a problem with the functioning of neurons.
In older individuals, paresthesia is often the result of poor circulation in the limbs (such as in peripheral vascular disease, also referred to by physicians as PVD or PAD), most often caused by atherosclerosis, the build up of plaque within artery walls, over decades, with eventual plaque ruptures, internal clots over the ruptures and subsequent clot healing but leaving behind narrowing of the artery openings or closure, both locally and in downstream smaller branches. Without a proper supply of blood and nutrients, nerve cells can no longer adequately send signals to the brain. Because of this, paresthesia can also be a symptom of vitamin deficiency and malnutrition, as well as metabolic disorders like diabetes, hypothyroidism, and hypoparathyroidism.
Irritation to the nerve can also come from inflammation to the tissue. Joint conditions such as rheumatoid arthritis and carpal tunnel syndrome are common sources of paresthesia. Nerves below the head may be compressed where chronic neck and spine problems exist and can be caused by, amongst other things, muscle cramps which may be a result of clinical anxiety or excessive mental stress, bone disease, bad posture, unsafe heavy lifting practices or physical trauma such as whiplash. Paresthesia can also be caused simply by putting pressure on a nerve by applying weight [or pressure] on to the limb for extended periods of time. Another cause of paresthesia, however, may be direct damage to the nerves themselves, i.e. neuropathy, which itself can stem from injury or infection such as frostbite or Lyme disease, or which may be indicative of a current neurological disorder. Chronic paresthesia can sometimes be symptomatic of serious conditions, such as a transient ischemic attack, motor neuron disease, or autoimmune disorders like multiple sclerosis or lupus erythematosus. The herpes zoster virus can attack nerves causing numbness instead of pain commonly associated with shingles. A diagnostic evaluation by a doctor is necessary to rule these out. Demyelination diseases may also cause cross-talk between adjacent axons and lead to parasthesia. During impulse conduction some aberrant current that escaped a demyelinated axon can circulate in the exterior and depolarize an adjacent demyelinated, hyperexcitable axon. This can generate impulses conducted in both directions along this axon since no part of the axon is in a refractory state. This becomes very serious in conditions such as multiple sclerosis and Guillain-Barre Syndrome.
Acroparesthesia is severe pain in the extremities, and may be caused by Fabry disease, a type of sphingolipidosis.
Anticonvulsant drugs such as topiramate, sultiame, and acetazolamide
Anxiety and/or Panic Disorder
Carpal tunnel syndrome
Chronic regional pain syndrome CRPS, also known as Reflex sympathetic dystrophy RSD
Guillain-Barre Syndrome (GBS)
Hydroxy alpha sanshool - a component of Sichuan peppers
Immune deficiency, such as Chronic inflammatory demyelinating polyneuropathy (CIDP)
Low blood-sugar (Hypoglycemia)
High blood-sugar (Hyperglycemia)
Pyrethrum and Pyrethroid (Pesticide)
Nitrous Oxide, long term exposure 
Spinal disc injury or herniation
Vitamin B5 deficiency
Vitamin B12 deficiency
Withdrawal from certain SSRIs, such as paroxetine
Intravenous administrating of strong pharmaceuticals acting on CNS, mainly opioids, opiates, narcotics. Especially in non-medical use (drug abuse)
*******I have this same thing! I have every test know to man! And they have found NOTHING!!! MRI's, CT scans, EMG, EEG, Etc,,,the list goes on and on! They think my symptoms are part stress/ and perhaps fibromyalgia!
I still get all of these symptoms, to this day! I give up on them, i try to ignore them now.*******