With a low intake and not much water to drink, urine may not be abundant. Other causes such as.
Excessive excretion: diarrhoea, vomiting, fever and sweating can also lead to reduced urine output.
Renal insufficiency: reduced glomerular filtration rate and problems with the kidneys lead to reduced urine output.
Urinary tract obstruction: kidney and ureteral stones, tumours and prostate enlargement lead to reduced urine output.