Chloride plays an important role in acid and electrolyte balance, kidney and muscle function, and the transport of minerals, water, and gases. Both high and low blood chloride levels can cause health issues. Keep reading to learn more about low chloride levels and the symptoms and disorders caused by it.
Disclaimer: The symptoms and conditions we discuss here are commonly associated with low chloride, but low chloride levels alone are not enough for a diagnosis. Work with your doctor to discover what underlying condition might be causing your low chloride levels to develop an appropriate plan to improve your health.
Symptoms of Low Chloride (Hypochloremia)
Low chloride levels (<95-100 mEq/L) are referred to as hypochloremia,.
Symptoms of severe chloride deficiency are normally related to metabolic alkalosis (high blood pH) and include [1, 2]:
- Irregular heart rate
- Cramps in muscles and nerves
Metabolic alkalosis occurs when blood pH increases above 7.45, becoming too basic. During metabolic alkalosis, the body naturally compensates by slowing its breathing rate, causing a buildup of CO2 in the blood [3, 4].
Causes of Low Chloride Levels
1) Excessive Chloride Loss
Blood chloride levels can drop if it is excreted in excessive amounts through the kidneys or through the digestive system .
Through the kidneys, this is due to:
- Excessive use of diuretics [6, 7]
- Genetic defects of electrolyte channels in the kidneys (e.g., Bartter’s and Gitelman syndromes) [8, 9]
- High concentration of carbon dioxide in the blood with increased bicarbonate intake (respiratory acidosis) [10, 11]
- Excess levels of the hormone aldosterone in blood 
Through the digestive system, this is due to:
- Frequent vomiting 
- Abuse of laxatives 
- Stomach pumping 
- Evacuation through a surgical opening of the end of the bowel through the belly (ileostomy) 
- Narrowing of the opening of the stomach into the bowel 
- Watery diarrhea 
- Secretion through tumors in the bowel (McKittrick-Wheelock syndrome) 
2) Insufficient Chloride Intake
The recommended minimum daily intake of chloride is 2.3 g. Because the average adult consumes 5.8-11.8 g/day, chloride malnutrition is very rare .
A soy-based formula with very low chloride content (0-2 mEq/L) caused low blood chloride levels and metabolic alkalosis in babies in a study on 13 people. It also occurred in 4 out of 153 babies with mothers with eating disorders [20, 21].
Similarly, a liquid nutritional product for individuals with severe disabilities caused chloride deficiency in a study on 59 people .
Cystic tissue scarring is a hereditary syndrome that causes low blood chloride levels because it is not absorbed through the kidneys and bowel .
3) Excess Fluid Intake
Infusion with high volumes of low-salt fluids reduces the concentration of electrolytes (including chloride) in the blood .
An anorexic woman who drank large amounts of water developed low blood chloride, sodium, and potassium levels, as well as headache, vomiting, and seizures .
People with congestive heart failure retain large amounts of fluids and develop resistance to diuretics, which causes low blood chloride levels .
The excessive release of the antidiuretic hormone vasopressin causes an increased return of water to the blood circulation by the kidneys and thus reduces electrolyte levels .
4) Metabolic Alkalosis
Metabolic alkalosis (high blood pH) is a result of :
- Increased bicarbonate production/intake
- Decreased bicarbonate excretion
- Loss of hydrogen ions
Some causes of metabolic alkalosis include [3, 4]:
- Medications, like diuretics that increase urination of hydrogen ions
- Kidney issues that reduce the urination of HCO3-
- Taking too many antacids
The loss of a positively charged electrolyte (hydrogen) and/or buildup of a negatively charged electrolyte (bicarbonate) promotes the elimination of chloride to balance positive and negative charges [29, 30].
Infusion or intake of high volumes of sodium bicarbonate causes blood alkalosis and may lead to chloride being exchanged for bicarbonate to maintain blood neutrality .
5) Electrolyte Imbalance
Because the blood concentration of positively charged electrolytes must equal that of negatively charged electrolytes, conditions that cause the loss of sodium and potassium often result in low blood chloride levels .
Low Chloride Levels & Genetics
The following genetic conditions are associated with abnormally low chloride levels.
2) Bartter’s Syndrome
Bartter’s syndrome is a rare inherited defect of the kidney cells in the part of the kidney that reabsorbs electrolytes (loop of Henle) and is characterized by :
- Potassium wasting
- Low blood chloride levels
- Metabolic alkalosis (high blood pH)
- High blood renin levels
- High aldosterone secretion
- Normal blood pressure
- High urine prostaglandin levels
- Frequent need to drink and urinate
The syndrome is caused by mutations in the Na+/K+/2Cl- cotransporter 2 (NKCC2), as well as in the following related proteins :
- ROMK (a protein that moves potassium out of the cells)
- ClC-Kb (a protein that moves chloride out of the cells)
- CaSR (a protein that detects calcium levels and uses them as a signal to activate electrolyte transporters)
3) Gitelman’s Syndrome
Gitelman’s syndrome is a hereditary disease with similar symptoms to Bartter’s (metabolic alkalosis with low potassium, low chloride, high renin, and high aldosterone levels in the blood), but due to defects in the kidney cells of a different region (distal convoluted tubule). The condition is caused by mutations in the Na+/Cl- cotransporter (NCCT) [34, 35].
4) Cystic Tissue Scarring
Cystic tissue scarring is a hereditary disorder characterized by the following symptoms :
- High salt concentration in sweat
- Mucus buildup
- Frequent lung diseases
- Damage in the airways
- Frequent coughing
- Pancreatic failure
- Development of diabetes
- Low bone mineral density
- Kidney failure
- Inability to grow and gain weight (in children)
- Blood clotting disorders
Regarding electrolyte balance, cystic tissue scarring causes low blood levels of chloride, sodium, and potassium, and high levels of bicarbonate .
5) Addison’s Disease
Addison’s disease is a rare hereditary disorder in which the glands above the kidneys are defective and produce low levels of the hormones cortisol and aldosterone. The main symptoms of this disorder are :
- Generalized weakness and tiredness
- Loss of appetite
- Weight loss
- Craving for salt
- Darkening of skin areas
- Low blood pressure
- Low blood levels of sodium and chloride
- High blood levels of potassium
Addison’s disease is due to mutations in:
- AIRE (a gene causing autoimmune diseases in several organs) 
- ABCD1 (a protein that transports fatty acids) 
- DAX-1 (a protein that ensures the correct development of the kidneys and glands above them) .
- ALADIN (a protein of the nuclear envelope) 
6) Congenital Chloride Diarrhea
Congenital chloride diarrhea is a rare genetic disease characterized by the production of watery diarrhea with high chloride concentration. It causes dehydration, metabolic alkalosis, and low levels of blood chloride, sodium, and potassium. The condition is due to defects in the bowel chloride and bicarbonate transporter SLC26A3 [42, 43].
7) Syndrome of Inappropriate Antidiuresis
This syndrome is characterized by reduced water elimination, continued production or action of the antidiuretic hormone vasopressin, and low blood sodium and chloride levels .
The disease is caused by activating mutations in the vasopressin receptor AVPR2, which leads to the excessive accumulation of water .
Consequences of Low Chloride Levels
1) Low Chloride Levels and Death Rate
A relationship between low blood chloride levels and increased death rate has been demonstrated in several studies on:
- Over 9000 healthy people 
- Almost 6000 people with heart failure [47, 48, 49, 50]
- Almost 1500 critically-ill people [51, 52, 53]
- Over 3000 people recovering from a stroke 
- Almost 300 people with excessive blood pressure inside the lung vessels 
Similarly, low blood levels of chloride, sodium, and albumins due to malnutrition reduced the survival of HIV patients taking antiretroviral therapy in a study on over 600 African women .
2) Low Chloride Levels and Kidney Function
The incidence of kidney injury increased in patients with low blood chloride levels in a study on over 13000 people undergoing contrast-enhanced tomography .
In another study on over 6000 critically ill people, low blood chloride was a risk factor for the development of kidney injury .
Factors that May Help Increase Blood Chloride
The most important thing is to work with your doctor to treat any underlying conditions causing your low chloride levels. The additional strategies below are other things that you may try if you and your doctor determine that they could be appropriate.
1) Medications Review
Note: By writing this section, we are not recommending changes in your medication schedule. We are simply providing information that is available in the scientific literature. Please discuss your medications with your doctor.
Low blood chloride levels can be caused by drugs such as:
On the other hand, the following drugs may lower blood chloride levels and reduce metabolic alkalosis:
- Carbonic anhydrase blockers 
- Diuretics 
- Corticosteroids (short-term treatments) 
- Arginine hydrochloride 
- Ammonium chloride 
- Lysine chloride 
- Potassium chloride 
Your doctor may review your medications and recommend dosage adjustments or medication changes based on your symptoms.
2) Eating Chloride-Rich Foods
Chloride is normally consumed as salt (60% chloride) or salt-containing foods. Additional foods with relatively high chloride contents include [67, 68]:
- Stock cubes (16%)
- Olives in brine (3%)
- Bacon (2.9%)
- Prawns (2.5%)
- Salami (2.5%)
- Blue cheese (2.3%)
- Butter (1.3%)
- Bread (0.9%)
3) Fluid Therapy
Chloride electrolyte losses can be replaced through infusion with 0.9% sodium chloride solution .
Limitations and Caveats
Although the studies covered in this post were mainly human studies, a large number of them were retrospective cohort studies. Because these studies look at existing data, the data may be inaccurate, incomplete, or inconsistently measured. Thus, most of the data collected is only correlational (shows a relationship between the factors) and not causal (determines a cause and effect) .
Chloride blood levels are usually measured as part of an electrolyte or metabolic panel. Values below 95-105 mEq in adults and children are considered low (also known as hypochloremia).
Potential causes include excessive chloride loss (such as from vomiting, watery diarrhea, laxative abuse), low-salt infusions, metabolic alkalosis, and many underlying electrolyte imbalances.
Although very rare, low chloride blood levels can also be caused by drinking large amounts of water, not getting enough chloride from food, and certain genetic disorders.
Low chloride levels are not enough for a diagnosis. Your doctor will assess your overall symptoms and lab test results for an accurate diagnosis and treatment.
- High Chloride Levels (Hyperchloremia) Symptoms & Causes
- Chloride Blood Test: Normal Electrolyte & Chloride Levels