Acupuncture is very effective form of pain control in that it can relieve soreness in three ways. First, it causes the body to produce chemical hormones called endorphins, which inhibit the perception of pain naturally. It blocks the transmission of pain signals to the brain through the nervous system.
Secondly, it activates trigger points. Trigger points (ashi points) are tender and extremely reactive areas that develop within the muscles. The points have typically developed a condition of either stagnation or stasis due to an injury, or the invasion of an exogenous or endogenous pathogen such as cold, heat, damp, dry, wind or fire.
Thirdly, all needled points signal the growth of new stem cells from bone marrow to help create new cells and tissues for repair. Stem cells have the remarkable potential to develop into many different cell types in the body during early life and growth. In addition, in many tissues they serve as a sort of internal repair system, dividing essentially without limit to replenish other cells as long as the person or animal is still alive. When a stem cell divides, each new cell has the potential either to remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell, a red blood cell, or a brain cell.
Angina is a choking, squeezing or pressure like feeling in the chest brought on by activity and quickly relieved by rest or a nitro tablet. It usually results from a large heart artery that's severely blocked, but many patients have apparently normal arteries on angiography, and disease of small arteries is also suspected.
The angina is the result of a lack of oxygen supply to active heart muscle cells. Perhaps by reducing the activity of the sympathetic nervous system to the heart muscle (the fight or flight system), selected patients with angina respond to acupuncture with less symptoms and better ability to walk long distances.
Just as my patient Billie taught me, the heart is an energy organ with every heart beat controlled by a wave of electricity and recovery. Furthermore, while the heart is richly supplied by nerve fibers originating in the brain, it also has many nerve communications from the heart back to the brain. With every breath in, the heart rate should speed up subtly; with every exhale, it should slow down, something that can be measured as the heart rate variability, or HRV. The better your HRV the healthier you are.
Acupuncture has been shown to improve the HRV in humans. Furthermore, studies of various heart rhythm problems show promise for reducing or eliminating the distress of palpitations such as atrial fibrillation.
Many studies throughout the world have been given on a range of arthritis sufferers from patients awaiting full-hip replacements, to knee surgery patients, as well as people suffering from the affects of rheumatoid and osteoarthritis. In most studies, the patients are split into groups- one group participating in acupuncture and Chinese medicine treatments in conjunction with a self-help course for managing their condition and conventional therapy; the other group receiving only the conventional therapy and self-help course information. The studies indicated that between 25-40 percent who received acupuncture in conjunction with the conventional and self therapy had a decrease in pain and a noted improvement in function of arthritic joints.
The latest study by the US National Institutes of Health (NIH) is one of the largest and longest clinical trials to show such conclusive effects and patients who underwent acupuncture treatment reported a 44% average reduction in pain and a 40% improvement in mobility.
The American College of Physicians formally recommends acupuncture for the treatment of back pain. Published in the prestigious Annals of Internal Medicine, clinical guidelines were developed by the American College of Physicians (ACP) to present recommendations based on evidence. Citing quality evidence in modern research, the ACP notes that nonpharmacologic treatment with acupuncture for the treatment of chronic low back pain is recommended. The official grade by the ACP is a “strong recommendation.” 
A major goal of the recommendation is for acupuncture and other nonpharmacological therapies to replace drug therapy as a primary source of pain relief. Treatment with opioids is only recommended, with an official “weak recommendation,” when other modalities do not provide adequate relief. A strong recommendation is also made by the American College of Physicians for the treatment of both acute and subacute lower back pain with heat, massage, acupuncture, and spinal manipulation.  The recommendations were approved by the ACP Board of Regents and involves evidence based recommendations from doctors at the Penn Health System (Philadelphia, Pennsylvania), Minneapolis Veterans Affairs Medical Center (Minnesota), and the Yale School of Medicine (New Haven, Connecticut).
The American College of Physicians notes that approximately 25% of USA adults have had, at the very minimum, a one day lower back pain episode within the past three months. The socioeconomic impact of lower back pain in the USA was approximately $100 billion in the year 2006 . The costs include medical care and indirect costs due to lost wages and declines in productivity.  Recommendations for treatment options, including those for the use of acupuncture, include considerations of positive medical patient outcomes, the total number of back pain episodes, duration between episodes, alleviation of lower back pain, improvement in function of the back, and work disability reductions. Recommendations are for both radicular and nonradicular lower back pain.The target audience for the American College of Physicians recommendations includes all doctors, other clinicians, and the adult population with lower back pain. The ACP notes, “Moderate-quality evidence showed that acupuncture was associated with moderately lower pain intensity and improved function compared with no acupuncture at the end of treatment .”  In agreement, the National Institute of Neurological Disorders and Stroke (National Institutes of Health) notes that acupuncture is an effective treatment modality for the relief of chronic lower back pain. These findings are consistent with those published in Mayo Clinic proceedings finding that acupuncture is effective for the treatment of lower back pain. The same Mayo Clinic report notes that acupuncture does not cause any significant adverse effects. 
The Mayo Clinic findings apply to both nociceptive and non-nociceptive pain. Nociceptive back pain includes musculoskeletal inflammation and pain involving nerve cells wherein nociceptors are activated. Nociceptors are afferent neurons in the skin, muscles, joints, and other areas. For example, nerve impingement (often referred to as a “pinched nerve”) produces one type of nociceptive pain.Non-nociceptive pain does not involve inflammation and is more relevant to pain processing in the central nervous system. One type of non-nociceptive pain condition is fibromyalgia and acupuncture has been confirmed as an effective treatment modality for this condition. The Mayo Clinic proceedings note, “Martin et al. found a significant improvement between electroacupuncture vs sham electroacupuncture. Differences were seen on the Fibromyalgia Impact Questionnaire (FIQ) scores for fatigue and anxiety.” 
1. Qaseem, Amir, Timothy J. Wilt, Robert M. McLean, and Mary Ann Forciea. "Noninvasive Treatments for Acute, Subacute, and Chronic Low Back Pain: A Clinical Practice Guideline From the American College of PhysiciansNoninvasive Treatments for Acute, Subacute, and Chronic Low Back Pain." Annals of Internal Medicine (2017).
2. Qaseem, et al. Annals of Internal Medicine (2017).3. Katz J.N. Lumbar disc disorders and low-back pain: socioeconomic factors and consequences.J Bone Joint Surg Am200688 Suppl 2214.
4. Lam M. Galvin R. Curry P. Effectiveness of acupuncture for nonspecific chronic low back pain: a systematic review and meta-analysis.Spine (Philadelphia, Pennsylvania 1976) 201338212438.
5. ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Low-Back-Pain-Fact-Sheet. Low Back Pain Fact Sheet, National Institute of Neurological Disorders and Stroke, National Institutes of Health.
6. Nahin, Richard L., Robin Boineau, Partap S. Khalsa, Barbara J. Stussman, and Wendy J. Weber. "Evidence-based evaluation of complementary health approaches for pain management in the United States." In Mayo Clinic Proceedings, vol. 91, no. 9, pp. 1292-1306. Elsevier, 2016.
7. Martin DP, Sletten CD, Williams BA, Berger IH. Improvement
in fibromyalgia symptoms with acupuncture: results of a randomized
controlled trial. Mayo Clin Proc. 2006;81(6):749-757.
University of California School of Medicine researchers have proven that acupuncture lowers blood pressure in subjects with hypertension.  The depth and breadth of the research extends across multiple university controlled studies. The investigations also reveal how acupuncture works; the biological mechanisms stimulated by acupuncture are no longer a mystery. The University of California School of Medicine, Irvine, researchers determined several key items. Acupuncture produces long-lasting lowering of blood pressure in subjects with hypertension. Acupuncture regulates sympathetic nervous system responses resulting in lower blood pressure in cardiovascular related centers of the brain and “specific neurotransmitter systems.”  In addition, their cross-over double blinded research identifies specific acupuncture points and procedures that are especially effective for lowering blood pressure.The researchers note that electroacupuncture is effective “at two sets of standardized acupoints known to provide input to brain stem regions that regulate sympathetic outflow lowers blood pressure….”  They highlight three key points. First, electroacupuncture that is administered once per week in 30 minute acupuncture sessions over a period of 8 weeks is effective for lowering blood pressure in patients with hypertension.  Second, results are observed by the second week of acupuncture therapy and last for 4–6 weeks if no follow-up treatment is administered after completion of the 8 weeks of acupuncture therapy.  Third, monthly acupuncture maintenance treatments maintain the healthy low blood pressure for at least 6 months. The University of California School of Medicine researchers find electroacupuncture a mediator of the autonomic nervous system. Plasma norepinephrine and renin-aldosterone measurements indicate that electroacupuncture lowers blood pressure by downregulating sympathetic nervous system outflows. 
This mechanism resulted in a lowering of both systolic and diastolic blood pressure in subjects with hypertension. Furthermore, the researchers successfully differentiated acupuncture points that were effective from those that were not.
1-7 Tjen-A-Looi, Stephanie C. "Reduction of Blood Pressure by Electro Acupuncture in Mild to Moderate Hypertensive Patients: Randomized Controlled Trial." Journal of Intensive and Critical Care 3, no. 1 (2017):
There are several studies on how acupuncture is stimulating new stem cells. The first paper studied rats with spinal cord injuries. One group received “Governor-Vessel” electro-acupuncture plus stem cells surgically implanted into the damaged spinal cord, the second group got only the stem cells, and the third was a control. The acupuncture group had greater survival and engraftment (more of the stem cells attached and thrived) than the other two groups. The acupuncture treated rats also had more stem cells with greater differentiation into spinal cord nerve cells. The second study investigated whether rats with a spinal cord injury that were treated with electro-acupuncture would stage a better recovery and why. Sure enough, the acupuncture treated rats had better stem cells in the injured spinal cord, better growth factor levels associated with nerve repair, and also recovered more limb movement! The third study created brain injury in rats to determine the effects of acupuncture on the natural repair process. While the group with only the brain injury had a lower number of brain stem cells, the acupuncture treated rats had more stem and progenitor cells involved in brain repair.
Who knew acupuncture could be such a powerful modulator of stem cell function (at least in lab rats)? In fact, there 72 published studies right now, many focusing on the use of Governor-Vessel electro-acupuncture to help the brain or spinal cord repair.
Fortunately rates of usage have dropped but smoking is still the number 1 root cause of deaths due to heart disease and cancer. Acupuncture is one of the modalities that may help the nicotine addicted patient to successfully quit this habit. Over 3,000 patients have been studied in randomized trials of the role of acupuncture to quit smoking and most favor a positive effect.