Use very thin needles which usually does not cause significant pain.

Acupuncture is generally safe but can lead to the complications seen with any type of needle use. Local complications may include bleeding, contact dermatitis, infection, pain, and paresthesia. Practitioners should use sterile needles to prevent transmission of disease. In the United States, acupuncture practitioners are required to use disposable sterile needles. A prospective study in Japan of 65,482 acupuncture treatments reported no major adverse events..

Pregnancy is not an absolute contraindication, since acupuncture has been used and studied for gestational conditions such as breech presentation and pregnancy-associated nausea. According to acupuncture theory, however, some points can induce labor, and the acupuncturist should be informed of the pregnancy. 

Acupuncture should be avoided in patients with severe neutropenia as seen after myelosuppressive chemotherapy. The insertion of acupuncture needles at sites of active infection or malignancy is contraindicated. In the case of malignancy, there is a theoretical risk of causing metastatic dispersal of tumor cells. Electroacupuncture should be avoided in patients with an automatic implantable cardioverter-defibrillator or pacemaker because of risk of electrical interference with the device. Traditional acupuncture is safe in these patients.

Bleeding disorders and use of anticoagulants are also not contraindications to acupuncture treatment, with no increased incidence of bleeding complications among patients taking antiplatelet agents, direct oral anticoagulants or warfarin. The acupuncturist should, however, be notified of any bleeding risks.