Neuropathy (peripheral), Paresthesias / Numbness / Tingling: Ddx

Diabetes mellitus
Idiopathic peripheral polyneuropathy
Compression of the spinal cord or peripheral nerves.
Disk disease
Carpal tunnel syndrome
Meralgia paresthetica
Herpes Zoster
Alcoholism
Stroke
Guillain-Barré syndrome
Hypothyroidism; Hyperthyroidism
Deficiencies of: Vitamin B12, folate, B6 deficiency; Thiamine (B1). Also, Vitamin B6 excess.
Multiple sclerosis
Multiple myelomas
Monoclonal gammopathy of undetermined significance (MGUS)
Psychiatric; hyperventilation syndrome
Drugs: Statins, Metronizadole, Nitrofurantoin, Phenytoin, Heroin, Isoniazid, pyridoxine, hydralazine, chloroquine, vincristine, amiodarone, lithium, others
Heavy metal poisoning: lead, mercury, arsenic, gold, thallium
Industrial agents or pesticides: acrylamide, organophosphates, Hexacarbon solvents, methyl bromide, carbon disulfide
Cauda equina syndrome
Brain or cord tumor
Amyloidosis
HIV/AIDS
Paraneoplastic syndrome e.g lung cancer
Lymphoma
Hypocalcemia
Copper deficiency
Chronic liver disease
Renal insufficiency; ESRD; Uremia
Lyme disease
Syphilis
Diphtheritic polyneuropathy (a complication of diphtheria)
Hereditary neuropathies (e.g., Charcot-Marie-Tooth)
Arylsulfatase A deficiency
Porphyria
Sarcoidosis
Leprosy (Hansen’s disease)
Neuropathy associated with critical illness
Hereditary neuropathy with liability to pressure palsies
Cryoglobulinemia
Polyarteritis nodosa
Rheumatoid arthritis
Giant cell arteritis (Temporal arteritis )
Friedrich’s ataxia
Dejerine-Sottas disease (HMSN type III)
Refsum disease (HMSN type IV)
Chronic inflammatory demyelinating polyneuropathy (CIDP)
Toxic neuropathy
Poliomyelitis
Periodic paralysis syndrome

Thinking through the differential diagnosis
Peripheral vs. Central neuropathy.
The differential may be categorized according to mechanisms of disease (VINDICATED MEN)

In about 25% of people with peripheral neuropathy, the cause isn’t identified after a thorough evaluation. These patients are categorized as having idiopathic polyneuropathy.

Further Reading

Am Fam Physician. 2010 Apr 1;81(7):887-892. Peripheral Neuropathy: Differential Diagnosis and Management. https://www.aafp.org/afp/2010/0401/p887.html