Diabetes Mellitus: This condition is a common cause of weight loss and tingling sensations in the hands due to peripheral neuropathy, which is a result of high blood sugar levels damaging the nerves.

Hypothyroidism: Weight loss and neuropathic symptoms like tingling in the hands can be associated with hypothyroidism, especially if the condition is severe and untreated.
Vitamin B12 Deficiency: A deficiency in vitamin B12 can lead to neurological symptoms including tingling in the hands and feet, along with weight loss due to gastrointestinal symptoms.
Chronic Alcohol Abuse: Alcohol abuse can lead to nutritional deficiencies (including vitamin B12 deficiency) and direct toxic effects on the nerves, causing weight loss and tingling sensations.

Multiple Myeloma: Although rare, this cancer can cause weight loss and neuropathy. Missing this diagnosis could be fatal, so it's crucial to consider it, especially in older adults with unexplained weight loss and neurological symptoms.
Lymphoma: Similar to multiple myeloma, lymphoma can present with systemic symptoms like weight loss and may cause neuropathy, either directly or through associated paraneoplastic syndromes.
Amyloidosis: This condition involves the deposition of abnormal proteins (amyloid) in various tissues, including nerves, and can cause weight loss and neuropathic symptoms.

Sjögren's Syndrome: An autoimmune disorder that can cause neuropathy and may be associated with weight loss, though it's more commonly known for its effects on exocrine glands.
Porphyria: A group of disorders that can result in neurological symptoms, including neuropathic pain and tingling, along with gastrointestinal symptoms that may lead to weight loss.
Heavy Metal Poisoning (e.g., Lead, Mercury): Exposure to certain heavy metals can cause neuropathy and systemic symptoms like weight loss, though this would typically be associated with a clear exposure history.