Hyperventilation Syndrome: This condition is characterized by rapid and deep breathing, leading to a drop in carbon dioxide levels in the blood. It can cause lightheadedness, numbness or tingling around the mouth and in the extremities, and is often triggered by stress or anxiety. The symptoms presented are classic for hyperventilation syndrome, making it the most likely diagnosis.

Anxiety or Panic Attack: Similar to hyperventilation syndrome, anxiety and panic attacks can cause lightheadedness and numbness or tingling sensations due to hyperventilation and increased stress response.
Vitamin B12 Deficiency: A deficiency in vitamin B12 can lead to neurological symptoms, including numbness or tingling in the hands and feet, though lightheadedness is less common. It's a consideration, especially in individuals with dietary restrictions or malabsorption issues.
Electrolyte Imbalance: Abnormal levels of electrolytes such as potassium, sodium, or calcium can lead to muscle weakness, numbness, and lightheadedness. This could be due to various reasons, including dehydration, certain medications, or underlying kidney or hormonal disorders.

Stroke or Transient Ischemic Attack (TIA): Although less likely given the specific combination of symptoms, it's crucial not to miss a stroke or TIA, as timely intervention is critical. Numbness, especially if it's unilateral, and sudden onset of symptoms should prompt an immediate evaluation for stroke.
Myocardial Infarction (Heart Attack): While the symptoms don't classically suggest a heart attack, atypical presentations can occur, especially in women, diabetics, or the elderly. Lightheadedness could be a sign of decreased cardiac output.
Severe Hypoglycemia: Low blood sugar can cause lightheadedness, confusion, and numbness or tingling sensations. It's particularly concerning in diabetic patients, especially those on insulin or certain oral medications.

Multiple Sclerosis: An autoimmune disease affecting the brain and spinal cord, multiple sclerosis can cause numbness or tingling in various parts of the body. However, it typically presents with more localized neurological deficits and would be an uncommon cause for the specific combination of symptoms described.
Peripheral Neuropathy: Conditions affecting the peripheral nerves can lead to numbness or tingling, but they usually have a more gradual onset and are associated with other symptoms such as pain or weakness.
Mitochondrial Myopathies: Rare genetic disorders affecting muscle and nerve function, these conditions can cause a variety of symptoms including numbness, tingling, and lightheadedness, but are much less common and typically present with additional systemic or muscular symptoms.