The lymphatic system can be thought of as a secondary circulatory system, with its fluid carrying immune cells throughout the body. When the lymph nodes, which act as filters, are removed, damaged or infected, the flow can be disrupted. This disruption can cause swelling, called lymphedema, as fluid builds up in the circulatory vessels and tissues.

Lymph drainage therapy (LDT), or manual lymphatic drainage, is a recognized medical therapy in at least one area of conventional medicine: for treatment of the swelling that can occur in an arm or leg after surgery, especially for breast or prostate cancer. There is an insurance code for LDT, and when the treatment was used for our son Gideon, we had no problem being reimbursed at the normal out-of-network rate by our insurance carrier. Although the medical community generally shuns LDT except for post-surgical conditions, there are a few MDs, including Marie Steinmetz, who prescribe it in other cases.

Ioana Razi, a pediatrician in the District, often refers patients with lymphatic and other special needs to either Pamela Wood, the physical therapist who treated my son, or an osteopath, a physician with additional training in manipulative therapy.

Like other physical therapists, Wood cannot perform LDT for a specific medical condition without a doctor's prescription. There is no national standard of certification for physical therapists performing LDT.

Wood has consulted and shared treatment of lymphatic patients with several osteopaths in this area.

Some LDT advocates say even laypeople can perform simple treatments on patients with minor lymphatic problems -- for example, a child with an ear infection or a cold. Osteopath Mary Ann Block outlines the procedure in her book "No More Amoxicillin" (Kensington Books, 1998); Razi distributes relevant pages to her patients.

There is no single nationally recognized credential for a lymph drainage therapist. However, the Lymphology Association of North America (www.clt-lana.org) certifies lymphedema therapists. This association and the Upledger Institute (www.upledger.com), home of LPT authority Bruno Chikly, who developed the techniques used by Wood, maintain directories of therapists who have been qualified through their programs.

As with any medical treatment, a willingness to ask questions, check references and scrutinize credentials is the patient's best defense.

-- Deborah R. Simons