Vomiting with Abdominal Pain Unrelated to Food and Without Fever (Metabolic Causes)

CLINICAL DIAGNOSTIC MANUAL

Vomiting associated with abdominal pain that is not related to food intake and does not present fever, can have various metabolic causes. These conditions involve alterations in the chemical and hormonal balance of the body, such as in diabetic ketoacidosis or hypercalcemia, which can trigger these symptoms without any evident relation to diet or infections. Given that some of these conditions can be potentially serious or require urgent treatment, a thorough clinical evaluation and complementary tests are essential to identify the underlying cause and establish appropriate management.

Pathology	Symptoms and Clinical Signs	Suspicion Diagnosis	Confirmation Diagnosis
Drug overdose	Nausea, vomiting, abdominal pain, confusion, lethargy, dizziness, seizures or respiratory difficulty depending on the drug.	History of overdose or recent drug intake, gastrointestinal and neurological symptoms.	Plasma levels of the involved drug. Toxicological tests.
Diabetic ketoacidosis	Nausea, vomiting, abdominal pain, Kussmaul respiration, fruity breath, dehydration. Common in poorly controlled type 1 diabetes.	Patient with a history of diabetes, hyperglycaemia, and symptoms of metabolic decompensation.	Arterial blood gases with metabolic acidosis. Elevated blood glucose, ketone bodies in blood and urine.
Hypercalcemia	Abdominal pain, nausea, vomiting, weakness, confusion, lethargy, dehydration.	Patient with abdominal symptoms, lethargy, and elevated serum calcium levels.	Elevated blood calcium levels. Elevated PTH if primary hyperparathyroidism is suspected.
Addison’s disease	Nausea, vomiting, abdominal pain, hyperpigmentation, weakness, hypotension, adrenal crises that may lead to shock.	Persistent hypotension, weight loss, and gastrointestinal symptoms. Family history of adrenal disease.	Low cortisol levels, elevated ACTH. ACTH stimulation test.
Acute intermittent porphyria	Severe abdominal pain, nausea, vomiting, neuropathy, confusion, mood changes. Intermittent episodes.	Unexplained abdominal pain in a young patient, episodes triggered by drugs, fasting, or stress.	Elevated urinary excretion of delta-aminolevulinic acid (ALA) and porphobilinogen. Genetic confirmation in specific cases.
Pheochromocytoma	Abdominal pain, nausea, vomiting, hypertension, palpitations, headaches, excessive sweating.	Patient with episodic severe hypertension and symptoms associated with catecholamine release.	Elevated catecholamines in urine or plasma. CT or MRI showing adrenal tumour.
Lead poisoning	Abdominal pain (saturnine colic), nausea, vomiting, fatigue, irritability, anaemia, neurological alterations.	History of lead exposure, neurological and gastrointestinal symptoms.	Elevated blood lead levels. Radiography of long bones showing lead lines (in chronic cases).
Vitamin A poisoning	Nausea, vomiting, abdominal pain, blurred vision, skin peeling, headache, intracranial hypertension in severe cases.	History of high intake of vitamin A supplements.	Elevated blood levels of vitamin A. Brain CT in cases of suspected intracranial hypertension.