Dear Doctors: What causes nasal stuffiness when you don’t have a cold or allergy? My nose sometimes gets stuffy when I lie down, then clears up when I stand. Blowing my nose yields nothing. Even when I have a cold, it will open up if I exercise. What can help when you have a stuffy nose?

Dear Reader: The stuffy nose you have been dealing with is called rhinitis. “Rhino” refers to the nose, and “itis” indicates the presence of inflammation.

In addition to congestion, symptoms of rhinitis include sneezing, nasal itching, reduced sense of smell and a runny nose. The condition can be classified as allergic and nonallergic rhinitis. As the name plainly states, allergic rhinitis arises from an immune response to the presence of an allergen. Nasal inflammation with no apparent cause is referred to as nonallergic rhinitis. Being stuffed up from a cold or the flu also falls under that category.

The nasal cavity is served by a dense and complex network of blood vessels. It is also lined with a thin layer of mucus that keeps the tissues moist and flexible, and which contains immune cells that defend against foreign invaders. When something causes the blood vessels in the nasal passages to become inflamed, they swell up. This leads to congestion that can range from mild to severe. When the tissues swell, they also slow the flow of mucus. As mucus accumulates, it can contribute to stuffiness.

It also appears that certain immune cells within the nose can trigger an inflammation response, even when infection or allergens are not present.

Nonallergic rhinitis has a wide range of triggers. They include potential irritants such as perfumes; cleaning products; secondhand smoke, smog or other air pollutants; spicy foods; hot beverages; changes to the weather; hormonal fluctuations; pet dander; dry air; and certain medications.

While nonallergic rhinitis can also include an overproduction of mucus, it is not always present. When congestion is due mostly to swelling and not to an abundance of mucus, as in your case, blowing the nose brings no relief.

As many people with a chronic stuffy nose know, lying down can make things worse. That’s because while you’re upright, gravity helps your sinuses drain. But when you lie down, the effect is negated, and congestion occurs. Elevating your head -- whether with pillows or by sitting or standing up -- increases nasal drainage, often quite quickly. The increase in blood circulation that comes with light exercise can also widen the nasal passages, which makes breathing easier.

If your doctor has ruled out allergy, infection or sinus problems as a cause, there are steps you can take to get relief. Using a humidifier can be helpful, as can saline sprays. You also can use a daily saline rinse, but, as we have written in previous columns, always be sure to use sterilized water. Antihistamine sprays and decongestants can reduce symptoms, but their effect is temporary. Some people find that external nasal dilator strips, which manually open the airways, make breathing easier. They can be particularly helpful when sleeping.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctors: Several years ago, I began sweating on my forehead. It gradually became more profuse, until my entire head was soaking wet. My internist diagnosed hyperhidrosis. An antiperspirant he suggested worked, but only briefly. What is the cause of hyperhidrosis? Is there any treatment?

Dear Reader: Hyperhidrosis is a disorder in which the sweat glands become overactive. The result is excessive perspiration that is not associated with exercise, temperature or any other typical triggers. Parts of the body that are commonly affected include the palms of the hands, armpits, soles of the feet, chest, the head and face. This last type of excessive sweating is known as craniofacial hyperhidrosis.

For the majority of people, hyperhidrosis does not pose a serious health threat. However, it can be uncomfortable and embarrassing, and it can interfere with quality of life.

Excessive sweating linked to a known cause, such as menopause, Parkinson’s disease, low blood sugar or an overactive thyroid gland is known as secondary hyperhidrosis. When it arises with no clear cause, it is known as primary hyperhidrosis.

The reason this disorder occurs is not fully understood. However, it is believed to be linked to a glitch in the workings of the sympathetic nervous system, which oversees the body’s fight-or-flight response and acts as its thermostat. Genetics may also play a role. It appears that when someone has primary hyperhidrosis, the brain is sending signals that activate the sweat glands, even though the conditions that would require the cooling effects of sweat are not present.

When it comes to managing the disorder, the antiperspirant your internist recommended is a common first-line approach. So are medications known as anticholinergics, which interfere with the electrical signals the body uses to activate the sweat glands. Beta blockers, which are medications that mask the physical manifestations of anxiety, are also sometimes prescribed. In some cases, patients opt for an endoscopic surgery called thoracic sympathectomy, in which certain nerves associated with sweating are severed.

Nerve impulses associated with sweating can also be muted with the use of Botox. That’s the product name for an injectable protein made from Botulinum toxin, which is a neurotoxin. Botox injections have come to be widely used in managing primary hyperhidrosis when topical treatments have failed. The treatment works by blocking the nerve signals that instruct the sweat glands to become active. It takes three to four days for the results of Botox injections for hyperhidrosis to become evident. Depending on each person, as well as the area beating treated, the results last for up to six months.

According to the International Hyperhidrosis Society, people who receive Botox injections have found excessive sweating decreases by more than 85%. Side effects of the treatment can include pain, swelling and bruising at the injection site. Although Botox is widely used for many types of hyperhidrosis, at this time, it has been FDA approved only for excessive underarm sweating. When used for other areas of the body, it is an off-label use.

With the failure of the antiperspirant to bring you relief, your internist can advise you on whether oral medications, Botox injections or surgery may be an appropriate next step.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctors: I was surprised to find out that a co-worker gave his nephew a kidney several years ago. He never mentions it and I don’t want to invade his privacy, but I would like to know more about the process. What does it take for someone to donate a kidney? Is it safe for them to do it?

Dear Reader: Your co-worker is what is known as a living donor. It’s just as it sounds -- the donation of an organ by someone who is still alive.

The kidney is the most frequently transplanted organ from a living donor. While less common, it is also possible to donate a lobe of the liver, all or part of a lung, a portion of the pancreas or part of the intestines. The majority of the 6,000 organs provided by living donors each year come from relatives, loved ones or close friends. A small number come from a donor who has chosen to help someone they don’t know but who is in great need. Whatever the circumstances, becoming a living donor is a weighty decision that requires serious thought.

Depending on the transplant center, the prospective donor must be at least 18 or 21 years old. They must also be mentally competent to make the decision to donate and be in good health. Conditions that can interfere with becoming a living organ donor include diabetes, cancer, uncontrolled high blood pressure, hepatitis, HIV or an active infection. All of this is ascertained during the evaluation that is required of all potential donors. This begins with blood tests and tissue typing to see if a potential donor is a good match. If so, the person undergoes additional testing, including heart and lung exams, a colonoscopy, and liver and kidney function tests.

Not surprisingly, given the enormity of such a decision, a mental health assessment is an important part of the screening process. The transplant center also makes sure the donor has the financial, medical and personal support required when someone undergoes major surgery.

The transplant itself is done under general anesthesia and takes three to four hours. Most kidney transplants are now done laparoscopically, which means small incisions and a faster recovery time. The timing of a return to work and a regular routine varies, but typically takes three to six weeks.

Short-term risks to the donor include those involved in any surgery. These include infection, pain, blood clots and an adverse reaction to anesthesia. Long-term risks include the natural decline in kidney function that accompanies aging and developing a disease that itself impedes kidney function. This includes Type 2 diabetes, high blood pressure and obesity. A donor loses 25% to 35% of their kidney function. To compensate, the remaining kidney increases in size.

The data show that donating a kidney does not affect the donor’s life expectancy. People on the kidney transplant list wait an average of three to five years for an organ. Tragically, some don’t survive the wait. In donating a kidney to his nephew, your co-worker has made a courageous and generous choice.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)