Many readers have inquired about conditions that cause bodily swelling,
especially in the legs. Some time ago I did a column on varicose veins, but
that was just one part of the edema story. We are all aware of the
cardiovascular system that takes blood away from the heart, releasing
oxygen and nutrients, and returns blue spent blood to the source. But the
heart, arteries and veins almost pale in importance to the much less talked
about Lymphatic System.
Just like the pipes in your plumbing system, arteries and veins are not
perfect conduits. They spring leaks. Add to this the fact that substances
and gases diffuse from the vessels right into bodily tissues, and one is
left wondering what happens to the protein, fluid, and nutrients that
escape? How do they get back into circulation? What happens if they don't?
The lymphatics are a network of very tiny vessels that lie adjacent to the
regular blood vessels. They absorb lost fluid and protein like sponges and
transport them up distinct channels to the veins near the heart. In earlier
columns I described how red blood is pumped through the body actively by
the heart. Venous blood, you will recall, returns usually against gravity,
by an ingenious combination of muscle action and one-way valves. Much like
veins, lymph transport is powered in part by the squeezing action of
muscles. By the time the fluid is pushed up a series of one-way valves to
the chest, the negative pressure that is created every time we inhale
vacuums it the rest of the way to its destination in the blood stream.
Lymph fluid is usually clear which explains the origin of the term which is
the Latin lympha meaning water.
But lymph is responsible for much more than recycling. It is the major
highway and troop transport system for ""soldier cell" defenders against
unwelcome invaders. Phagocytes are cells that line the lymph vessels,
waiting to gobble up bacteria and foreign material that enter the body
through a variety of routes, Lymphocytes are special troops that identify
the enemy and actually clone thousands of target-specific cells which
either attack the problem with chemical bombs or use other special tactics
to neutralize only the immediate threat without harming innocent bystander
Another fascinating job of the lymph system is to absorb the fat from our
intestines. In fact, after a meal (especially a fatty one) the clear lymph
fluid becomes milky and is called Chyle (from the Greek chylos meaning
The tiny lymph channels often congregate in a series of pea-sized nodes in
various strategic locations in the body. You can feel these nodules in
places like your neck, armpit, and groin, especially if there is an
infection or local inflammation brewing. These nodes act like barracks and
mustering points for the various specialized "soldier cells" of the immune
system. They become large and tender if infection or cancer spreads to the
area. This is why doctors usually biopsy lymph node chains; for when cancer
spreads here from a turnout site the enemy has already penetrated major
defense strongholds and the prognosis often worsens.
Besides the node clusters under the skin there are many internal
groups of lymphoid tissue such as the tonsils in the throat and adenoids at
the back of the nose which guard the body's entrances from potentially
harmful particles and organisms.
Despite the fact that the lymph vessels are so tiny they can rarely even be
seen during surgery, there are times when one is only too aware of their
presence. Scratches, bites, slivers, and almost any source of infection of
the extremities can be accompanied by red streaks (lymphangitis) up the
limbs. Some people used to refer to this as "blood poisoning" which is a
misnomer since blood isn't necessarily involved. The streaks usually
terminate at painful lumps in the elbows, armpit or groin
The lymphatic-immune system has some powerful allies besides nodes and
lymph vessels. The spleen is a fist sized organ with a number of
interesting functions. It acts like a sponge storing red blood cells until
exercise or hemorrhage causes it to squeeze its reserves into the system.
It is also a kind of junkyard that traps and destroys old defective blood
cells, recycling their components. Along with other parts of the lymph
system, the spleen filters out debris or infectious organisms, and
participates in the immune processes aforementioned. Because it is so
stuffed with blood, this organ is often ruptured during serious blunt
trauma and may have to be removed to prevent the victim from hemorrhaging.
Amazingly, despite all its important functions, many people live relatively
normal lives when their spleens are gone. This is largely thanks to the
rest of the lympho-immune system that handles many of the spleen's
The thymus is a small flat gland in the chest that is also involved in
producing immune soldier cells especially in the early years of life. Many
of the "soldier cell" lymphocytes present in the thymus, spleen, and
elsewhere, are actually born in the bone marrow along with their cousins,
the red blood cells. Beginning as generic or stem cells, they eventually
grow up to perform different functions depending on the body's needs. In
fact, in serious immune compromising diseases, such as HIV infection or
AIDS, we judge the progress of the illness based upon the number and type
of lymphocytes available to fight invaders.
In previous columns I discussed conditions such as congestive heart failure
and varicose veins that can cause soft tissue swelling in dependent areas
of the body. If you survive a clogged artery type of heart attack you will
probably at least pay the price of losing a chunk of heart which dies and
forms a scar. The weak portion of the scar can then behave like an old
fragile balloon. Picture a situation when you try to fill a deflated old
wiener shaped balloon. The weakest flaccid part blows up and may stretch
inordinately, but the air does not progress further down to the more
elastic portion where you want it to go. Analogously, in the heart, instead
of squeezing the blood to where it has to go, the injured part just
balloons up and cannot empty properly. The blood may back-up in the system
congesting the lungs (creating shortness of breath) and into the legs
creating swelling and pain. This is called congestive heart failure. In
some very large sized individuals, congestive heart failure can result
because the heart may not be able to keep up with the workload needed to
cover all tissues.
LIP0DEMA AND LYMPHEDEMA
Lipodema (Lipo=fat) is a condition more common in large women and often
more pronounced in those who have some history of major weight loss.
Unfortunately, the weight usually leaves the upper body more easily than
the legs and thighs, leaving tender adipose tissue that often droops over
ankles. If pain is debilitating, plastic surgery may be required.
Heat and humidity as well an imbalance of bodily hormones,
elements, water or sugar and, of course, tight clothing can all cause
swelling especially in dependent areas. Swollen ankles and feet at the end
of a long hot day often leave a sock or other impression at pressure
In some circumstances, however, the edema is not "pitting" but
somewhat rubbery or firm. Lymphedema occurs when there is obstruction,
damage, or malformation to lymph vessels. If the pipes are not working, all
the fluid and substances that the lymphatics usually drain away from a limb
stay put, causing tightness and firm, often painless, swelling. A person
can be born with the condition but more usually it is the result of
infection, trauma, burns, radiation therapy, or surgical scarring. In any
case, protein continues to enter the tissue from the blood stream and a
build-up happens in the tissues the lymphatics should be draining. The
excess protein can cause chronic inflammation and excess fibrous tissue.
This can cause more blood capillaries to form and to be dilated, and the
limb feels hot. The heat, combined with the stagnant protein provides an
opportunity for bacterial growth.
Severe lymphedema can decrease mobility, cause embarrassment and a
general loss of quality of life.
Lymphedema cannot be completely cured, but the condition can be
greatly improved through a variety of steps. These are a) complex physical
therapy, b) the use of benzo-pyrone drugs (where allowed), c) compression
garments or bandaging, and d) special exercises. Some of these can and
should be used in conjunction. ß