Dehydration can sometimes cause a person’s sweat, urine, or breath to have an ammonia-like odor. When the body is dehydrated, it tries to conserve water by reducing urine output. The less diluted urine can have a stronger odor, sometimes described as an “ammonia smell.” Severe dehydration can also cause ketoacidosis which produces acetone-like breath. While dehydration may contribute to ammonia-like odors, other factors are usually involved including diet, hygiene, underlying health conditions, and medications.
What causes ammonia smell with dehydration?
Concentrated urine
When the body is dehydrated, the kidneys conserve water by limiting urine output. Less water output means the urine is more concentrated with waste products including urea. Urea breaks down into ammonia, giving urine a stronger “ammonia-like” smell when dehydrated.
| Hydration Level | Urine Volume | Urea Concentration | Ammonia Smell |
|---|---|---|---|
| Well Hydrated | Higher | Diluted urea | Faint/no smell |
| Dehydrated | Lower | Concentrated urea | Stronger ammonia smell |
So having an “ammonia odor” to urine can be a sign of dehydration as the kidneys conserve water. But other factors like certain foods, supplements, or urinary tract infections may also contribute.
Incomplete metabolism
With severe dehydration, cells can’t properly metabolize nutrients. This leads to byproducts like ammonia and ketones building up. The ammonia scent is breathed out when the lungs expel excess ammonia. Ketones like acetone give breath a fruity or metallic smell.
Kidney dysfunction
Kidneys also filter out waste products like urea from blood. Dehydration strains the kidneys and causes incomplete filtration. This allows more ammonia into urine. Those with chronic kidney disease are prone to an ammonia odor even when well hydrated.
Other causes of ammonia smell
While dehydration can lead to an ammonia odor, several other factors can contribute:
Diet
Certain foods like protein supplements, cruciferous vegetables, and high protein diets can increase urea content in urine. Medications like aspirin or antibiotics that alter urine pH can allow more ammonia to be excreted.
Infections
Urinary tract, vaginal, and other infections disturb compounds in urine and sweat leading to increased ammonia-like smells.
Stress
Stress causes hormonal changes that can increase sweat production and alter its chemical makeup. Stress sweat tends to contain more ammonia.
Smoking
Tobacco smoke exposes the skin and urine to compounds that are expelled as ammonia-like odors. Second-hand smoke can have a similar effect.
Poor hygiene
When sweat, urine, and waste products remain on the skin for prolonged periods without washing, bacteria can thrive and produce ammonia-like smells.
Liver or kidney disease
Dysfunctional livers or kidneys allow built up toxins like ammonia to enter the blood then excrete out in urine or sweat. This causes an ammonia or bleach-like smell even when hydrated.
Genetics
A small percentage of people have a genetic condition called “trimethylaminuria” that prevents them from breaking down certain compounds. This leads to increased trimethylamine in sweat and urine which smells like ammonia or rotting fish.
Who is at risk for ammonia smell with dehydration?
While anyone can develop an ammonia odor when dehydrated, some groups are at increased risk:
| Group | Reason for Increased Risk |
|---|---|
| Infants and young children | Limited reserves of fluid, higher metabolism |
| Elderly adults | Reduced thirst reflex, medications causing fluid loss |
| Intense athletes | Heavy sweating during exercise without fluid replacement |
| Outdoor workers | Prolonged heat exposure and sweating |
| Chronic illness | Disease effects on hydration, kidney function |
| Poor fluid intake | Inadequate water, over-caffeination, alcohol use |
Those who already have kidney impairment are also prone to ammonia smells even when not dehydrated. Certain medications like diuretics, antihistamines, antipsychotics, and others can increase risk of dehydration as well.
Preventing ammonia smell from dehydration
Strategies to help prevent or reduce ammonia odors related to dehydration include:
Drink adequate fluids
Drink enough non-caffeinated, non-alcoholic beverages to produce frequent, pale urine. About 3 liters for men and 2.2 liters for women daily is recommended. Thirst is not a good indicator of need.
Monitor hydration
Check the color and volume of urine. Pale yellow to clear urine in good amounts means you are well hydrated. Dark yellow or amber urine in small amounts signals dehydration.
Replace fluids during illness
Dehydration risks increase with fever, vomiting, diarrhea which deplete fluid reserves. Drink electrolyte solutions.
Avoid excessive protein
Eating less protein and protein supplements can reduce ammonia production and odor.
Increase fiber intake
Fiber helps draw water into stools and avoid dehydration from diarrhea.
Manage underlying conditions
Treat diabetes, kidney disease, urinary tract infections, or skin conditions that increase dehydration risks.
Improve hygiene
Bathe regularly, wear breathable fabrics, change undergarments frequently to reduce bacteria on skin.
Treating an ammonia smell
If simple hydration and hygiene measures don’t resolve an ammonia odor, other treatment options include:
Medications
Your doctor may prescribe antibiotics for infections, alpha blockers for kidney problems, acidifying medications to make urine less alkaline, or others targeting an underlying condition.
Diet changes
Reducing foods high in protein and urea like meat, dairy, fish, and eggs can lower smelly ammonia in sweat and urine. A dietitian can help plan nutrition adjustments.
Increased fluid intake
Drinking more water and staying well hydrated dilutes urine and reduces odor intensity. Citrus juice or vitamin C supplements can help acidify urine as well.
Frequent laundering
Wash clothing, bedding, and towels more often in hot water to kill bacteria that produce ammonia-like smells on fabric.
Probiotics
Taking probiotic supplements can restore healthy gut bacteria. This improves digestion and reduces ammonia production.
Liver support
Supplements like milk thistle or liver detox regimens can help support liver function and filter toxins to reduce odors.
Dialysis
For kidney failure, dialysis is used to filter the blood and remove waste products like urea that build up. This prevents ammonia odor.
When to see a doctor
Consult your doctor promptly if an ammonia smell persists or is accompanied by:
– Fever, nausea, vomiting, diarrhea indicating infection or dehydration
– Dark urine, decreased frequency of urination signaling kidney problems
– Yellow skin or eyes pointing to possible liver disease
– Metallic taste, rapid breathing from acetone-like ketones
– Dizziness, fainting, increased thirst and urination as signs of diabetes
– Unintentional weight loss which may reflect an underlying chronic condition
– No relief from improved hygiene and hydration
A doctor can order tests to check for infections, kidney function, glucose levels, and other factors that may be contributing to the ammonia smell. Prompt treatment of any underlying condition is recommended.
Conclusion
Mild ammonia-like smells from sweat or urine commonly occur with dehydration when the kidneys conserve water. Concentrated waste products and incomplete metabolism create the odor. However, ammonia smells can also arise from diet, infections, smoking, genetics, and chronic diseases. Staying well hydrated, practicing good hygiene, reducing protein intake, and promptly treating any underlying condition can help ameliorate an ammonia odor. Severe, persistent or unexplained ammonia smells warrant medical evaluation to assess for diabetes, liver or kidney disorders. With proper prevention and treatment, ammonia odors due to dehydration can often be avoided or resolved.