Natural Medicines rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

The Effectiveness ratings for Yoga are as follows:

Possibly Effective for…

• Asthma. Most research shows that yoga modestly improves symptoms and quality of life in patients with asthma.
• Back pain. Most research shows that yoga can help relieve chronic low back pain. Experts recommend that people with low back pain try exercises such as yoga before they consider taking pain medication. But there’s no evidence that yoga relieves low back pain better than other types of exercise.
• Depression. Yoga might help lessen depression symptoms in the short term. Yoga seems to work best in people with mild or new onset depression. Some experts recommend that people with mild or moderate depression consider yoga or other meditative practices as a first- or second-line therapy for depression. But yoga doesn’t seem to reduce depression symptoms better than usual care, group therapy, or social support groups in the long term.
• Diabetes. There is some evidence that practicing yoga for 3 months improves blood sugar control in people with diabetes. Yoga also seems to slightly improve cholesterol, lower heart beat rate, and lower blood pressure in these people.
• High blood pressure. Practicing yoga seems to modestly reduce blood pressure in people with high blood pressure. But there is some evidence that other types of meditation might work better.
• Menopausal symptoms. Most research shows that practicing yoga can help improve hot flashes, sleep, and other symptoms of menopause. Yoga seems to provide equal benefit compared with other exercise regimens.
• Pregnancy and delivery discomfort. Studies have shown that participating in a yoga program during pregnancy seems to improve comfort during labor, delivery, and for 2 hours after delivery. Yoga also appears to reduce the chance of early labor and some complications of pregnancy such as high blood pressure. Babies born to mothers who practiced yoga during pregnancy also seem to weigh more at birth than some other babies. Additionally, early research shows that yoga appears to modestly decrease depressive symptoms compared to standard prenatal care in pregnant women with and without prenatal depression.
• Stress. Practicing yoga seems to reduce stress and anxiety in people experiencing mild to moderate levels of stress. Yoga appears to work about as well as relaxation therapy or cognitive behavioral therapy.
• Tuberculosis (TB). Some research shows that practicing yoga for 2 months can decrease symptoms, increase weight, improve lung function, and lower the bacterial count in people with TB.

Possibly Ineffective for…

• Multiple sclerosis (MS). Practicing yoga does not seem to improve quality of life or ability to move compared to usual care or exercise in people with multiple sclerosis. However yoga practice does seem to help with fatigue.

Insufficient Evidence to Rate Effectiveness for…

• A childhood disorder involving difficult adjusting and anxiety. Early research suggests that practicing yoga and receiving massage can decrease anxiety and anxious behavior in children with adjustment disorder and depressed mood.
• Alcoholism. Early research suggests that yoga may improve the general condition and rehabilitation of alcoholics.
• Altitude sickness. Early research suggests that yoga trainees are better able to breathe and take in oxygen when moving to high altitudes.
• Anxiety. Some research suggests that yoga might improve symptoms of anxiety in people with anxiety disorder. But some researchers think these results may not be reliable because the studies were not well designed.
• Athletic conditioning. Early research suggests that practicing yoga for one year improves heart endurance and power.
• Attention. Early research suggests that practicing yoga for 2 weeks improves mental and physical energy and feelings of alertness and enthusiasm compared to relaxation or visualization exercises.
• Attention deficit-hyperactivity disorder (ADHD). There is some evidence that yoga improves some, but not all, symptoms of ADHD.
• Breast cancer. Some research shows that practicing yoga improves quality of life, tiredness, sleep, anxiety, and depression in women with breast cancer . Yoga seems to work about as well as other exercise programs for improving quality of life and tiredness in these women . In breast cancer survivors, yoga seems to improve quality of life and diarrhea .
• Bronchitis. Some people with chronic bronchitis report less shortness of breath after practicing yoga.
• Heart disease. There is limited research assessing the effects of yoga in heart disease. However, some research shows that yoga decreases risk factors of heart disease. For example, practicing yoga appears to lower blood pressure, lipid levels, and cholesterol levels. Further, yoga training for a year significantly reduces total cholesterol, “bad” low-density lipoprotein (LDL) cholesterol, and progression of disease in people with established coronary artery disease. Yoga practiced with other lifestyle changes such as meditation, diet, and exercise improves chest pain and other parameters in people with disease of the heart arteries.
• Carpal tunnel syndrome. There is some evidence that yoga might improve grip strength and decrease pain in people with carpal tunnel syndrome.
• Chemotherapy-related nausea and vomiting. Yoga seems to significantly decrease the number of times breast cancer patients feel sick and vomit after chemotherapy. It also seems to make nausea less intense. Some women feel sick in the stomach even when they just think about chemotherapy treatments yet to come. Yoga seems to help this, too.
• Mental function. Yoga appears to have positive effects on cognitive function. Some evidence shows that yoga slightly improves attention, thinking speed, decision-making ability, and memory especially in the short term. Yoga in school children was similar to physical activity at improving cognitive function.
• Chronic fatigue syndrome (CFS). Developing research suggests that yoga appears to improve fatigue in people with chronic fatigue.
• A lung disease called chronic obstructive pulmonary disease (COPD). Early research suggests that practicing yoga may improve exercise ability, exertion recovery, and shortness of breath in people with COPD.
• Early male orgasm (premature ejaculation). There is some evidence that practicing yoga may improve premature ejaculation.
• Eating disorders. Early research suggests that yoga does not improve psychological symptoms in college women that considered themselves to have eating disorders.
• Epilepsy. There is some evidence that using yoga and meditation along with the usual treatment might reduce the number of seizures experienced by people with epilepsy.
• Fibromyalgia. There is some evidence that yoga can significantly reduce pain in people with fibromyalgia.
• Heart failure. Early research shows that adding yoga practice to standard therapy improves exercise capacity and flexibility in people with heart failure.
• Hemodialysis. There is some evidence that yoga significantly reduces pain and sleep problems in people undergoing dialysis for kidney failure. Yoga also appears to improve results of some lab tests that indicate the severity of their kidney disease.
• HIV/AIDS. Early research suggests that yoga improves well-being in people with HIV/AIDS.
• Sleep problems (insomnia). There is some evidence that yoga can decrease the time it takes to fall asleep, increase sleep time, improve the feelings of being well rested, and improve other sleep measures in people who have a hard time sleeping.
• Irritable bowel syndrome (IBS). There is some evidence that practicing yoga decreases disability and anxiety in teenagers with IBS, but it doesn’t seem to help their digestive tract symptoms. Another study found that yoga decreases digestion problems in men who have the type of IBS that has diarrhea as the main symptom.
• Mental retardation. Early research suggests that yoga practice may improve the intelligence quotient (IQ) and social ability in children with mental retardation.
• Metabolic syndrome. Early research suggests that practicing yoga seems to improve energy levels but not wellbeing, stress, or blood pressure in people with metabolic syndrome.
• Migraine headache. Developing research suggests that yoga significantly reduces the number and severity of migraines in some people.
• Muscle soreness. Early research suggests that there is less muscle soreness after exercising in women trained in yoga compared to untrained women.
• Obsessive-compulsive disorder (OCD). Early research suggests that practicing Kundalini yoga improves symptoms of OCD and mood when compared to relaxation therapy. Additional early research suggests that yogic breathing improves symptoms in people OCD that are taking a drug known as fluoxetine (Prozac).
• Opioid withdrawal. Early research suggests that yoga improves recovery and rehabilitation as well as group psychotherapy in patients addicted to heroin and receiving therapy with methadone.
• Osteoarthritis. Developing research suggests that yoga can improve movement and decrease pain in people with osteoarthritis of the knee and hand.
• Swollen pancreas (pancreatitis). Participating in yoga seems to improve the quality of life in people with chronic pancreatitis.
• Performance anxiety. Some musicians who are afraid to take the stage seem to be less fearful after practicing yoga.
• Quality of life. Early research suggests that yoga helps improve well-being and quality of life in people with various diseases. Additional research suggests that yoga improves heart, breathing, and physical function in senior citizens.
• Rheumatoid arthritis (RA). Early research suggests that practicing yoga does not improve morning stiffness, grip strength, disability, or other symptoms in people with rheumatoid arthritis.
• Schizophrenia. Yoga seems to improve symptoms, social functioning, and quality of life when added to standard care in people with schizophrenia. However, adding yoga seems to be no more beneficial than adding other types of exercise to standard care.
• Stroke. Early research shows that yoga does not improve quality of life, motor function, or pain in most people recovering from stroke. However, yoga might help improve memory during stroke recovery. Yoga might also help with balance in movement in people paralyzed after stroke.
• Tension headache. Early research shows practicing yoga may decrease headaches and ability to tolerate headaches. Other early research suggests that practicing a specific yoga pose known as shavasana decreases tension headaches similarly as different type of therapy called biofeedback.
• Ringing in the ears (tinnitus). Early research shows that yoga improves mental problems impairment due to tinnitus.
• Fatigue.
• Neuropathy.
• Pain.
• Other conditions.

More evidence is needed to rate the effectiveness of yoga for these uses.