Lipitor is a medication that contains atorvastatin and is used to lower cholesterol levels in the blood. According to the sources provided, Lipitor side effects can range from mild to severe, and some can be serious. Common side effects of Lipitor include muscle and joint pain, diarrhea, constipation, and nausea. These side effects usually go away on their own and do not require medical attention [2]. However, some people may experience more severe side effects such as liver problems, muscle damage, and an increased risk of diabetes. These side effects are rare but can be serious and require immediate medical attention [1].

According to the National Health Service (NHS), the most common side effect of Lipitor is muscle pain or weakness. This can occur in up to 1 in 10 people taking the medication. In rare cases, Lipitor can cause a condition called rhabdomyolysis, which is a severe muscle breakdown that can lead to kidney damage [2].

Medical News Today also notes that Lipitor can cause liver damage in rare cases. Symptoms of liver damage include yellowing of the skin or eyes, dark urine, and abdominal pain. People with a history of liver disease or heavy alcohol use should be monitored closely while taking Lipitor [3].

In conclusion, while Lipitor is generally considered safe and effective, it can cause side effects ranging from mild to severe. Common side effects include muscle and joint pain, diarrhea, constipation, and nausea. Severe side effects such as liver problems, muscle damage, and an increased risk of diabetes are rare but require immediate medical attention. Anyone experiencing severe or concerning side effects while taking Lipitor should speak to their doctor right away [1][2][3].

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.nhs.uk/medicines/atorvastatin/side-effects-of-atorvastatin/
[3] https://www.medicalnewstoday.com/articles/drugs-lipitor-side-effects