Differential Diagnosis for Ammonia Gas Smell

• Single most likely diagnosis:
  • Urinary Tract Infection (UTI) - The ammonia smell is often associated with UTIs, particularly those caused by bacteria that split urea into ammonia, such as Proteus species. This smell can be especially noticeable in the urine of individuals with such infections.
• Other Likely diagnoses:
  • Dehydration - Concentrated urine can have a stronger, ammonia-like smell due to the higher concentration of waste products.
  • Kidney Stones - Some kidney stones, especially those caused by urinary tract infections, can lead to an ammonia smell in the urine.
  • Diet - Certain foods, like asparagus, can make urine smell differently, sometimes similar to ammonia, due to the body's breakdown of sulfur compounds.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
  • Diabetic Ketoacidosis (DKA) - Although less common, DKA can cause a fruity or acetone-like smell in the breath, but in some cases, the urine might have an ammonia-like odor due to the metabolic state.
  • Liver Failure - In advanced liver disease, the body's inability to metabolize toxins properly can lead to unusual odors, including an ammonia-like smell in breath or urine.
• Rare diagnoses:
  • Maple Syrup Urine Disease (MSUD) - A rare genetic disorder that can cause urine to smell sweet, like maple syrup, but in some cases, might be mistaken for an ammonia smell due to the metabolic byproducts.
  • Phenylketonuria (PKU) - Another genetic disorder that can lead to unusual body odors, sometimes described as musty or similar to ammonia, due to the accumulation of phenylalanine.
  • Isovaleric Acidemia - A rare condition where the body cannot properly break down a particular amino acid, leading to a sweaty foot odor, but might be confused with an ammonia smell in some cases.