Diabetes insipidus is a condition that causes excess urine production and persistent thirst. Syndrome of inappropriate antidiuretic hormone (SIADH) causes your body to retain too much water.
Diabetes insipidus is usually caused by underproduction of a hormone called vasopressin, but it can also develop if your kidneys aren’t properly responding to this hormone.
People with SIADH have the opposite problem. They produce too much vasopressin and retain too many fluids. It can develop due to difficulties with your pituitary gland or from excessive vasopressin produced from other sources such as cancer cells.
Read on to learn more about these two conditions that cause difficulties with your water balance.
How is ADH involved in SIADH and diabetes insipidus?
Diabetes insipidus and SIADH cause opposite problems. People with diabetes insipidus pass too much water, whereas people with SIADH retain too much. Both conditions can lead to complications.
Diabetes insipidus symptoms
The main symptoms of diabetes insipidus are:
- frequent urination that may cause pale-colored urine every 15–20 minutes
- feeling like you’re thirsty all the time no matter how much water you drink
craving cold water
Frequently needing to pee may disrupt your sleep and cause additional symptoms, such as:
SIADH causes your body to retain too much fluid, which can lead to a condition called hyponatremia. Hyponatremia is when your sodium levels are too low. It causes
In severe cases it can cause:
Diabetes insipidus causes
Diabetes insipidus can develop for one of
- Central diabetes insipidus: Central diabetes insipidus is characterized by a lack of adequate vasopressin secreted by your posterior pituitary gland. It might be caused by:
- Nephrogenic diabetes insipidus: Nephrogenic diabetes insipidus occurs when your kidneys don’t respond to vasopressin the way they should. It can be caused by:
- Dipsogenic diabetes insipidus: Dipsogenic diabetes insipidus, also called primary polydipsia, develops when problems with your hypothalamus cause you to feel thirsty and drink more than usual. It might be caused by:
- medication side effects
disorders or schizophrenia
- brain surgery or infections
- tumors near your hypothalamus
- Gestational diabetes insipidus: Gestational diabetes insipidus is a temporary condition that occurs during pregnancy due to the placenta creating too much of the enzyme that breaks down vasopressin.
SIADH usually develops as a complication of other medical conditions. Potential causes include:
- conditions affecting your brain such as:
- cancer, especially small cell lung cancer
- medications such as:
- carbamazepine (Tegretol)
- oxcarbazepine (Trileptal, Oxtellar XR)
- surgery, possible due to stimulation of pain sensors
- lung disease, particularly pneumonia
- low thyroid hormone levels or low pituitary hormones
- administration of vasopressin, desmopressin, or oxytocin to treat other medical conditions
- HIV infection
- genetic factors
SAIDH and diabetes insipidus both cause problems with water balance. Some of the underlying causes can be the same. For example, they can both be caused by brain tumors or genetic factors.
Both can also cause imbalances in electrolyte levels. Electrolytes are minerals dissolved into your bodily fluids. Disruptions to your electrolyte levels can cause many problems throughout your body, such as:
- mood changes
- cognitive changes
- muscle weakness
Diabetes insipidus and SIADH can be treated with medications to regulate your vasopressin levels and other treatments to help regulate your water balance. You may need additional treatments depending on your underlying cause.
If you have SIADH, your doctor might tell you to restrict your water intake to less than
A group of medications called vasopressin receptor antagonists can help counteract the effect of vasopressin in your body.
Diabetes insipidus can be treated with a synthetic version of vasopressin called desmopressin. This artificial hormone can be administered:
- by mouth
- through you nose
- by injections through your skin
- through an IV
Gestational diabetes insipidus usually doesn’t require treatment.
Diabetes insipidus isn’t the same as the more common diabetes mellitus, where levels of glucose in the blood are chronically high.
It’s possible to have both types of diabetes at the same time, although it’s rare. Researchers reported a case of a 72-year-old man with evidence of both in a 2018 case study.
It’s possible to develop both diabetes insipidus and SIADH, although it’s rare.
SIADH and diabetes insipidus are two conditions that cause problems with your fluid balance. People with diabetes insipidus urinate more frequently than normal and develop excessive thirst.
SIADH causes the opposite problem. People with this condition retain too much water, which can lead to problems such as low salt levels.
Both conditions are potentially treatable with medications and other treatments for the underlying causes.