Based on the provided sources, common side effects of Lipitor (atorvastatin) include:

1. Nasopharyngitis (inflammation of the throat and nasal passages) [1][2]
2. Musculoskeletal pain, including back pain and myalgia (muscle pain) [1][2]
3. Diarrhea [1][2]
4. Cold-like symptoms [2]
5. Joint pain [2]
6. Nausea [2]

Serious side effects of Lipitor include:

1. Rhabdomyolysis (breakdown of muscle fibers that can lead to kidney damage) [1][2][3]
2. Liver damage [1][2]
3. Memory problems [1]

It is important to consult a healthcare professional if experiencing any side effects while taking Lipitor. If experiencing severe side effects, seek immediate medical attention [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.drugwatch.com/lipitor/side-effects/>