What is hyponatremia?


  • Hyponatremia is a state when the concentration of sodium in your blood is lower than the normal range. 


  • The normal blood sodium levels lie between 135 and 145 milliequivalents per litre (mEq/L). Hyponatremia is considered when the sodium levels in your blood fall below 135 mEq/L.


  • Sodium is an electrolyte that helps maintain water content in and around the cell. It also helps maintain the balance between different body parameters, such as maintaining normal blood pressure, ensuring the proper operating of nerves and muscles, and regulating the body’s fluid balance. 


  • In hyponatremia, a few factors, including underlying medical conditions and drinking too much water, lead to diluting the sodium in your body. 


  • As the water levels in the body rise, water accumulates in the cells, causing them to swell up and giving rise to many health problems, some of which can be life-threatening. 


What are the symptoms of hyponatremia?


  • Nausea and vomiting
  • Headache
  • Confusion
  • Tiredness and lethargy
  • Restlessness and irritability
  • Weakness, spasms, or cramps in the muscles
  • Fits or seizures
  • Coma


When to see a doctor?


  • If you develop severe symptoms of hyponatremia like nausea, vomiting, seizures, or loss of consciousness, you must get an appointment with a nephrologist or an expert doctor. 


  • If you are at risk of developing hyponatremia and are aware of it, you can talk about it to your doctor and ask him questions about how you can avoid it. Depending on your symptoms, your doctor will recommend a treatment modality.


What are the causes of hyponatremia?


Hyponatremia can occur as a result of a number of lifestyle factors and medical conditions, including:


  • Medications: Certain medications, like diuretics, antidepressants, and painkillers, can interfere with the normal hormonal process and kidney functions that maintain sodium concentrations within the normal range.


  • Heart, kidney, and liver problems: Heart diseases like congestive cardiac failure and certain kidney and liver diseases can lead to the accumulation of fluids in your body. This further leads to dilution of sodium in the body fluids, lowering its overall level.


  • Syndrome of inappropriate antidiuretic hormone or SIADH: This medical condition is characterised by high levels of a hormone called antidiuretic hormone (ADH) that causes the body to retain water when it would normally excrete it in the form of urine.  


  • Dehydration: If you are dehydrated due to chronic, severe vomiting, diarrhoea, or any other reasons, it will increase ADH hormone levels and also make your body lose certain electrolytes, including sodium.


  • Drinking excessive water: If you drink large amounts of water within a short time, your kidneys won’t be able to excrete it efficiently, diluting sodium in the body fluids and lowering its overall levels. 


  • Addison’s disease: Hormonal diseases like adrenal gland insufficiency or Addison’s disease interfere with the ability of your adrenal gland to produce hormones important for maintaining the balance of sodium, potassium, and water in the body. Hypothyroidism or low thyroid hormone levels in the body can also lead to a low level of sodium in the blood.


  • Drugs: Ingestion of the recreational drug Ecstasy increases the risk of severe hyponatremia, which can sometimes be life-threatening. 


What are the risk factors for hyponatremia?


Certain risk factors enhance your risk of developing hyponatremia, including:


  • Age: Owing to age-related changes, intake of certain medications, and a greater chance of developing a chronic disease that affects the sodium levels in the body, older adults are more susceptible to developing hyponatremia.


  • Drugs: Certain medications, including thiazide diuretics, some antidepressants, and painkillers, increase the risk of developing hyponatremia. Additionally, the drug Ecstasy, which some people take for recreation, leads to fatal cases of hyponatremia.


  • Kidney diseases: Chronic kidney disease and kidney failure hamper the function of the kidney to excrete water, leading to accumulation of water in the body and dilutional hyponatremia. Other medical conditions that hamper water excretion, like SIADH and heart failure, are also risk factors.


  • Intense physical activity: People who drink large quantities of water while performing high-intensity activities like during marathons or triathlons are at higher risk of hyponatremia.


  • Hormonal changes: The female sex hormones have an effect on the body’s ability to maintain sodium levels. Therefore, premenopausal women are at a higher risk of developing hyponatremia-related brain damage. 


What is acute and chronic hyponatremia?


  • Acute hyponatremia: The sodium levels fall rapidly, giving rise to potentially life-threatening effects such as rapid swelling of the brain tissues, which can result in coma and death. 


  • Chronic hyponatremia: The sodium levels fall gradually over a period of 48 or longer. The symptoms and complications of chronic hyponatremia are mild to moderate. 


What measures can I take to prevent hyponatremia?


  • Keep track of associated medical conditions: If you have any conditions that contribute to hyponatremia like adrenal gland insufficiency or have risk factors for the same, getting treatment for those will help reduce the risk of hyponatremia


  • Be self-aware: If you take any prescription medications, most specifically diuretics and painkillers, talk to your doctor about their potential effects on your sodium levels.


  • Be mindful of your activities: While doing physically intense activities like running a race, drink only as much water as you lose due to sweating. Thirst and the colour of your urine are, at times, the best guide to direct you towards drinking the amount of water your body actually needs. If your body is in demand of more water, your urine is darker than usual.


How is hyponatremia diagnosed?


  • History: The first step toward diagnosing hyponatremia is by reviewing your medical history. Your doctor will ask questions about your medical history and any underlying conditions and conduct a complete physical examination of your body. 


  • Laboratory tests: Because the signs and symptoms of hyponatremia are vague and occur in many other conditions, it is not possible to diagnose it on the basis of history and medical examination alone. Your doctor will order blood tests like serum electrolytes and urine tests like urine sodium concentration and serum osmolality to confirm the diagnosis.


What is the treatment of hyponatremia?


  • To treat hyponatremia effectively, your doctor will aim to address the underlying cause, if possible. The treatment depends to a great extent on the cause of low sodium levels. 


  • You may simply need to cut down on your water intake, while you may need intravenous electrolyte fluids and medicines in other cases.


  • If your hyponatremia is moderate and chronic secondary to your diet, diuretics, or consuming excessive amounts of water, your doctor may recommend temporarily limiting the amount of fluid you take. He might also adjust the dosage of your diuretic use to increase the level of sodium in your blood.


  • In severe and acute forms of hyponatremia, the doctor may recommend a more aggressive treatment approach, including intravenous fluids and medications.


  • Intravenous fluids: IV sodium solution may be administered slowly to increase the sodium levels in your blood gradually. You will be required to stay in the hospital to continuously monitor sodium levels as a rapid correction might prove dangerous.


  • Medications: Medications to relieve the signs and symptoms of hyponatremia like headaches, nausea and seizures may be prescribed.


How to prepare for the appointment?


Get an appointment with your doctor if you are at a known risk of hyponatremia and are noticing symptoms like nausea, headaches, muscle cramps, or generalised weakness. If you are on the look-out for ways to prepare, here is some information to guide you through the appointment: 


  • Make a list of any symptoms you have been experiencing and write down the duration as well. Write any factors that you think aggravate or relieve your symptoms 


  • Write down your medical history, including other medical conditions you have for which you are receiving treatment and the names of all the medicines and supplements you are currently taking.


  • Take a close friend or family member you feel comfortable with along with you. There is a chance you might forget some of the instructions the doctor gives you, and they can help you with that. Also, they can provide assistance if you need immediate medical care.


  • Note down your queries and the questions you would like to ask your doctor. Here are the questions you can ask to clear any doubts you have about your condition.


  1. What do you think is the cause of my symptoms?


  1. What are the most common factors responsible for causing hyponatremia?


  1. How severe is my condition?


  1. What treatment options do you recommend?


  1. When do you expect my symptoms to go away?


  1. Do I need to worry about any long-term problems?


  1. How can I prevent being in a similar condition in the future?


What questions can I expect from my doctor?


Being ready with answers to the most expected questions your doctor might ask will help save time to go over any points you might need an in-depth explanation to. Here are the most common questions doctors ask from patients with hyponatremia:


  1. What are your symptoms, and for how long have you been having those?


  1. Do you have any kidney or heart problems?


  1. Do you have nausea, vomiting, or diarrhoea?


  1. Have you recently begun taking any new medicines?


  1. Do you think your symptoms have improved or worsened since they first developed?


  1. Do you have any symptoms, including mental changes, such as feeling confused, anxious, or depressed?


  1. Do you have a progressively worsening headache? 


  1. Do you consume recreational drugs? If yes, which ones?
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