Yes, if typhoid fever is left untreated, symptoms typically worsen in a progressive, week-by-week pattern. In the first week, mild fever, fatigue, headache, and abdominal discomfort appear, often resembling a common viral infection. By the second week, the fever becomes high and persistent, reaching around 103–104°F, and symptoms like abdominal pain, diarrhea or constipation, coated tongue, and rash (rose spots) may develop. In the third week, the illness can become severe, with delirium, dehydration, intestinal bleeding, or perforation if not treated promptly. Without medical care, these complications can become life-threatening, but with early diagnosis and antibiotics, recovery is typically smooth and complete.