A patient with hypoglycemia may show all of the following symptoms except:

Hypoglycemia, or low blood sugar, typically presents with a range of symptoms that are largely due to the body’s response to low glucose levels. Symptoms commonly associated with hypoglycemia include weakness and shakiness, confusion, and irritability. These manifestations are primarily the result of the body's immediate need for glucose for energy and the activation of the sympathetic nervous system, which causes physical signs of distress.

Weakness and shakiness occur because muscles and the brain depend on glucose as a critical source of energy, leading to a loss of muscle function and coordination. Confusion can arise because the brain is particularly sensitive to low glucose levels, which can impair cognitive function and lead to disorientation or difficulty concentrating. Irritability also stems from the body's neurochemical response to the stress of hypoglycemia, causing mood changes as the brain struggles to maintain normal function.

However, nausea and vomiting are not classical symptoms associated with hypoglycemia. While nausea can occur in various medical conditions, it is not a primary or direct result of low blood sugar levels and is more often linked to gastrointestinal issues or other systemic illnesses. Therefore, among the listed options, nausea and vomiting is the symptom that does not commonly present in cases of hypoglycemia.