Lithium is one of the oldest and most effective treatments for bipolar disorder, helping many people manage mood swings and reduce the risk of relapse. However, like any medication, it can cause side effects that range from mild and manageable to more serious. Understanding these potential side effects and why regular monitoring is important can help you use lithium safely and get the most benefit from treatment.
Key Takeaways
Lithium is highly effective but needs monitoring: It has a narrow safe range, meaning the helpful dose and the harmful dose are close together, so regular blood tests are essential.
Common side effects are often mild: Many people can have increased thirst, frequent urination, a mild tremor, or stomach upset, especially early on.
Some side effects are serious: Lithium can affect the kidneys and thyroid over time, and lithium toxicity is a medical emergency that requires immediate care.
What Is Lithium and How Is It Used?
Lithium is a mood stabilizer used to treat bipolar disorder. Lithium was first approved by the FDA as a mood-stabilizing medication in the 1970s and is still a first-line choice today. It is used for acute manic episodes and for long-term maintenance to prevent future episodes.
Bipolar disorder causes shifts between very high moods, called mania, and low moods, called depression. Lithium helps smooth out these swings. Because mood symptoms can overlap with other conditions, an accurate diagnosis matters. Lithium is also used off-label at times for mood symptoms in other conditions, including borderline personality disorder.
Lithium is a powerful medicine with a narrow therapeutic range. This means the amount that helps is close to the amount that can cause harm. For this reason, providers check lithium blood levels regularly and adjust the dose carefully.
Common Side Effects of Lithium
Most people who take lithium have some side effects, especially when starting the medicine, although many are manageable.
Increased thirst and urination: Lithium affects the kidneys, and roughly 20 to 40%of people who take it long term develop increased thirst and frequent urination.
Mild hand tremor: A fine shaking of the hands is common and often improves over time.
Nausea and stomach upset: Taking lithium with food can help with these side effects.
Weight gain: Some people notice gradual weight gain.
Fatigue or mild drowsiness
Acne or skin changes
Most of these effects are mild and may ease as the body adjusts. Telling your provider about bothersome symptoms can help. Moreover, a dose change may reduce them.
Serious Side Effects and Long-Term Risks
While many side effects are mild, lithium can also affect important organs, which is why ongoing monitoring is so important.
Kidney Effects
Because the kidneys clear lithium from the body, long-term use can affect kidney function. Lithium can make the kidneys less able to concentrate urine, leading to heavy thirst and urination. Providers check kidney function regularly. For most people, this monitoring keeps the kidneys healthy, and any early changes can be addressed by adjusting the dose or, in some cases, considering a different medicine. Drinking enough water and keeping follow-up appointments are simple ways to protect the kidneys during treatment.
Thyroid Effects
Lithium can lower thyroid hormone levels over time, which may cause tiredness, weight gain, and sensitivity to cold. Thyroid function is usually checked with blood tests, and an underactive thyroid can be treated if it develops.
Heart and Other Effects
Lithium can sometimes affect the heart, so providers may review heart health before and during treatment. Long-term use can also be linked to changes in calcium and parathyroid levels.
Lithium Toxicity: A Medical Emergency
The most serious risk of lithium is toxicity, which happens when the level in the blood becomes too high. Lithium toxicity can be life-threatening and requires immediate medical care.
Early signs can include worsening tremor, nausea, vomiting, diarrhea, drowsiness, and muscle weakness. More severe toxicity can cause confusion, slurred speech, unsteady walking, and, in serious cases, seizures.
Toxicity can be triggered by dehydration, certain other medicines, kidney problems, or taking too much lithium. Because the safe range is narrow, anything that raises the blood level can be dangerous. If you notice these warning signs, seek medical help right away.
The good news is that most cases of toxicity can be prevented. Staying well hydrated, keeping your salt and fluid intake steady, and not skipping or doubling doses all help keep lithium in the safe range. Illnesses that cause vomiting, diarrhea, or heavy sweating can quickly raise lithium levels, so it is wise to call your provider if you become sick. Regular blood tests are the best way to detect rising lithium levels early, before they become a serious problem. .
How Lithium Is Monitored
Monitoring is a vital part of taking lithium. Regular checks help keep the dose in the safe range and catch any effects on the body early.
Providers usually check lithium levels in the blood, especially when starting the medicine or changing the dose. Once a stable dose is found, these checks happen less often but continue over time. Blood tests also assess kidney function and thyroid function, since lithium can affect both. Some providers also check calcium levels.
These check-ins are also a chance to talk about how you are feeling, whether the medicine is helping, and whether any side effects are bothering you. Keeping your appointments is one of the best ways to stay safe on lithium.
Drug Interactions to Know
Lithium can interact with other medicines, and some interactions can raise lithium to dangerous levels. This is why it is important to tell every provider and pharmacist that you take it.
Common over-the-counter pain relievers known as nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, can raise lithium levels. Certain blood pressure medicines, including some diuretics and angiotensin-converting enzyme (ACE) inhibitors, can do the same. Even big changes in salt or fluid intake can affect how much lithium stays in the body. Before starting any new medicine or supplement, check with your provider.
Managing Your Lithium Medication
Managing lithium safely requires the right dose, regular blood tests, and ongoing follow-up. At Blossom Health, our mental health professionals provide personalized lithium management, including dose adjustments, monitoring for side effects, and reviewing your blood test results. With regular check-ins and expert guidance, we help you stay on track with treatment while reducing the risk of complications. Moreover, you can easily connect with a board-certified psychiatric provider through Blossom Health and start care covered by in-network insurance.
How to Take Lithium Safely
A few simple habits can lower the risk of Lithium side effects and toxicity, and they are easy to build into a daily routine once they become familiar.
Take lithium exactly as prescribed and at the same time each day.
Stay well hydrated and keep your salt intake steady, since big changes can affect lithium levels.
Keep all blood test appointments to monitor lithium, kidney, and thyroid function.
Tell every provider you take lithium, since some medicines, including certain pain relievers, can raise lithium levels.
Avoid stopping lithium suddenly, which can cause symptoms to return.
Medical Disclaimer
This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding a medical condition or medication. If you are experiencing a mental health crisis, contact the 988 Suicide and Crisis Lifeline by calling or texting 988.
Sources
StatPearls. Lithium. ncbi.nlm.nih.gov
StatPearls. Lithium Toxicity. ncbi.nlm.nih.gov
StatPearls. Mood Stabilizers. ncbi.nlm.nih.gov
Cleveland Clinic. Lithium Toxicity. clevelandclinic.org
MedlinePlus. Lithium Toxicity. medlineplus.gov
National Institute of Mental Health. Bipolar Disorder. nimh.nih.gov
National Institute of Mental Health. Mental Health Medications. nimh.nih.gov
Cleveland Clinic. Mood Stabilizers. clevelandclinic.org
