In Reiki, a practitioner places hands lightly on the client’s body or a slight distance away from the body. (ISTOCKPHOTO)

You might not think to call a balneotherapist when your face breaks out or a reflexologist when asthma flares. But alternative medical practices, no matter how weird they might seem, are gaining traction.

“Alternative therapy” refers to any health treatment not standard in Western medical practice. Beyond that, complementary and alternative therapies are difficult to define, largely because the field is so diverse: It encompasses diet and exercise changes, hypnosis, chiropractic adjustment and poking needles into your skin (a.k.a. acupuncture). Technically, “alternative” treatments are used in place of conventional medicine; when used alongside standard medical practices, alternative approaches are referred to as “complementary” medicine.

The benefits (or lack of benefits) of alternative therapies are far from clear, since there have been few large-scale randomized clinical trials of them. Still, in 2008, more than 38 percent of American adults said they had used some form of alternative medicine. Here is a guide to some of those treatments:

Acupressure. Acupressure is similar to acupuncture, but no needles are involved. Practi­tioners use their hands, elbows or feet to apply pressure to points along the body’s “meridians.” According to the theory behind acupressure, meridians are channels that carry life energy (qi, or chi) throughout the body. This reasoning holds that illness can occur when a meridian is blocked or out of balance; acupressure is thought to relieve blockages so energy can flow freely again, restoring wellness.

More research is needed, but some pilot studies have found positive results: Acupressure might decrease nausea for chemotherapy patients and reduce anxiety in people scheduled to have surgery.

Acupuncture. Though “acupuncture” may immediately bring needles to mind, the term actually describes an array of procedures that stimulate specific points on the body. The best-known technique consists of penetrating the skin with thin needles, and it’s used by millions of Americans each year.

Despite its popularity, controversy over acupuncture’s efficacy abounds. Some studies have found it helpful for chronic pain and depression, but evidence for many claims, including its benefits for low back pain, is mixed.

Aromatherapy. Aromatherapy uses essential oils (concentrated extracts from the roots, leaves, seeds or blossoms of plants) to promote healing. The oils can be inhaled, massaged into the skin or (in rare cases) taken by mouth, and each has a specific purpose: Some are used to treat inflammation or infections; others are used to promote relaxation.

Some studies suggest aromatherapy might reduce pain, depression and anxiety, but more research is needed to fully determine its uses and benefits.

Ayurvedic medicine. Also known as ayurveda, ayurvedic medicine originated in India centuries ago. Practitioners use a variety of techniques, including herbs, massage and specialized diets, with the intent of balancing the body, mind and spirit to promote overall wellness.

Studies of ayurveda are few and far between (perhaps because the practice includes such a wide variety of treatments), so it’s difficult to determine how effective it is.

Balneotherapy. Also known as hydrotherapy, balneotherapy involves the use of water for therapeutic purposes, and it dates as far back as 1700 B.C. It’s based on the idea that water benefits the skin and might treat a range of conditions, including acne, pain, swelling and anxiety; practitioners use mudpacks, douches and wraps in attempts to reap water’s rewards.

Proponents of the therapy cite findings that water might boost people’s immune systems, though research on balneotherapy’s effectiveness remains inconclusive.

Biofeedback. Biofeedback techniques are intended to help people to control bodily processes that normally happen involuntarily — such as heart rate, blood pressure, muscle tension and skin temperature — in order to improve conditions including high blood pressure, headaches and chronic pain. Patients work with a biofeedback therapist to learn relaxation techniques and mental exercises. In initial sessions, electrodes are attached to the skin to measure bodily states, but eventually the techniques can be practiced without a therapist or equipment.

Researchers still aren’t sure how or why biofeedback works—but a lot of research suggests it does work for some things. Relaxation seems to be a key component, as most people who benefit from the practice have conditions that are caused or exacerbated by stress.

Chiropractic. Chiropractic focuses on disorders of the musculoskeletal and nervous systems, including pain in the back, neck, joints, arms, legs and head. The most common procedure performed by chiropractors is “spinal manipulation” (a.k.a. an “adjustment”), which involves applying controlled force (typically, the chiropractor’s hands) to joints that have become “hypomobile.” The idea is that joints’ movements become restricted when surrounding tissues are injured either during a single event (tweaking a muscle during a weightlifting session) or through repetitive stress (sitting with poor posture for extended periods). Chiropractic adjustments of the affected area are intended to restore mobility and loosen the muscles, allowing the tissues to heal and the pain to resolve.

Studies of chiropractic suggest the practice can decrease some types of back pain and improve physical functioning. (The use of neck cracking can pose some risk.)

Homeopathy. Homeopathy functions in much the same way as a vaccine: It’s based on the principle of treating “like with like,” meaning a substance that causes adverse reactions when taken in large doses can be used — in small amounts — to treat those same symptoms. Homeopaths gather extensive background information on patients before prescribing a highly diluted substance, usually in liquid or tablet form, to jump-start the body’s natural systems of healing. Not enough high-quality studies have been done to evaluate the efficacy of homeopathy.

Naturopathy. Naturopathic medicine is premised on the idea of the healing power of nature. Naturopathic doctors are trained in both conventional and alternative medicines, and seek to understand the cause of a condition by exploring its mental, physical and spiritual manifestations in a given patient. Naturopathy typically involves a variety of treatment techniques including nutrition, behavioral changes, herbal medicine, homeopathy and acupuncture.

Because it involves so many different therapies, it’s difficult to design studies that target naturopathy’s effectiveness. That said, one study that evaluated the practice for low back pain found some positive results.

Reflexology. Reflexology involves applying pressure to specific areas on the feet, hands or ears. The theory is that these points correspond to different body organs and systems; pressing them is believed to positively affect these organs and a person’s overall health. (For example, applying pressure to a spot on the arch of the foot is believed to benefit bladder function.) People often use the therapy to complement conventional treatments for conditions including anxiety, cancer, diabetes, kidney function and asthma.

Some studies have found that reflexology can improve respiratory function in breast cancer patients, reduce fatigue and improve sleep — but a 2011 review found there is not good clinical evidence to suggest that reflexology is effective “for any medical condition.”

Reiki. Reiki is a form of energy healing based on the idea that a “life force energy” flows through everyone’s body. According to this philosophy, sickness and stress are indications that life force energy is low, while energy, health and happiness signify a strong life force. In a Reiki session, a practitioner seeks to “transfer” life energy to the client by placing his hands lightly on the client’s body or a slight distance away from the body. (Reiki can also be performed long-
distance.) The purpose is to promote relaxation, speed healing, reduce pain and generally improve the client’s well-being. For the most part, there’s no regulation for Reiki practitioners.

Studies of the practice’s efficacy are varied: Some suggest therapeutic touch may be helpful in some cases, but a 2008 review of randomized clinical trials said the value of Reiki “remains unproven.” Others have found it ineffective.