Factors causing recurrent aphthous ulcers are common & systemic infections, & nutritional deficiency.

Diarrheal illness is classified as acute watery, invasive (dysentery), or persistent diarrhea.

The main causes of dry cough are viral infection, allergies (exposure to irritants), and asthma.

The causes of productive cough are acute bronchitis, pneumonia, and exacerbation of chronic bronchitis.

Anaemia in children can be caused due to infections, haemoglobinopathies, and nutritional deficiency.

Gastroparesis is a gastrointestinal manifestation of diabetic autonomic neuropathy.

GERD is diagnosed by upper GI endoscopy, response to acid suppression, and esophageal pH monitoring.

Classification of allergic rhinitis is based on symptom duration and severity.

Globally, the most common cause for maternal anaemia in pregnancy is Iron Deficiency Anaemia (IDA).