Dear Doctor: What can be done about interstitial cystitis, or bladder pain syndrome? I'm told there's no cause or cure, and that some doctors don't even believe it exists.

Dear Reader: Interstitial cystitis is a chronic condition of the bladder that's five times more common in women than men. Patients with interstitial cystitis have pain, pressure or bladder spasms, with symptoms worsening when the bladder is full and improving after voiding. The condition also causes an increase in urinary frequency and urgency. Because people with these symptoms need to use the bathroom frequently, the condition is extremely disruptive to their lives. Further, these symptoms disrupt sleep in 70 percent of patients, creating feelings of fatigue.

Now let's look at the cause: a disruption in the cellular lining of the bladder. This disruption allows urinary irritants, or chemicals, to penetrate through the lining of the bladder, affecting both the nerves and muscle of the bladder. The nerve irritation can send feedback to the central nerves of the spine. The spinal cord sends signals to the bladder and pelvis relaying pain information, perpetuating the pain in a back-and-forth cycle.

Doctors don't have a clear understanding of the inciting event that causes this inflammation. Interstitial cystitis may originate from a bladder infection, or from bladder irritants, such as caffeine, alcohol, spicy foods and citrus.

I've seen enough patients with this syndrome to know that interstitial cystitis, or as some call it, chronic bladder pain, is very much real. That said, other causes for the symptoms must be ruled out, requiring urine tests to check for infection or even directly visualizing the bladder with cystoscopy.

The first treatment step is to eliminate behaviors and foods/drinks that irritate the bladder, meaning stopping all consumption of caffeine, alcohol and tobacco. You can also consider the restriction of spicy foods and citrus. The second step would be to consider behavioral modification to decrease the frequency of urination. One study, published in the Journal of Urology, showed that diet and behavioral changes decreased symptoms in 45 percent of patients.

Physical therapy with a therapist who specializes in interstitial cystitis can relieve some of the pain in the pelvic region by working on tender areas and increasing muscle stability in the lower abdomen. A 2012 study published in the Journal of Urology showed a 59 percent decrease in symptoms compared to 26 percent who did general therapeutic massage.

Amitriptyline, a tricyclic antidepressant with multiple uses beyond depression, has potential as well. In a 2010 Journal of Urology study, the drug -- given at 50 milligrams -- was shown to decrease symptoms in 55 percent of patients with interstitial cystitis. The problem is that many patients cannot tolerate the side effects of this dose, so I would consider doses of 10 milligrams to 20 milligrams.

Pentosan polysulfate sodium, which seems to protect the lining of the bladder, may help as well, and the sedating antihistamine hydroxyzine can aid patients who have symptoms of pain and frequency of urination during the night.

While interstitial cystitis is not a well-understood disease, it is certainly a diagnosable condition.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I'm having trouble keeping my New Year's resolution to get more exercise, and one of my co-workers swears that an activity tracker or an exercise app will help me stay focused. What are they, exactly, and why would they work?

Dear Reader: First, let us reassure you that you're not alone. By deciding to exercise more, you've committed to creating a new habit, and that's always a challenge. There's the honeymoon phase, when you're buoyed by elation and optimism, and when getting out every day for a walk or a run or a trip to the gym is a snap.

However, this is often followed by a period of struggle as reality sets in. No matter the scope of the goal, you've committed to a process that moves gradually, in increments, and requires consistent willpower. Suddenly, finding an excuse to skip that yoga class is all too easy.

But take heart. For those who don't give up, who power through the disruption and uncertainty that a new activity can bring, there comes a magic moment. Suddenly, the new behavior has become second nature. It's a habit, a part of your life.

For those who decide to make exercise a new habit, an activity tracker or an exercise app can make that difficult middle phase bearable. They help you set a goal, track your progress and keep a diary of your effort. A recent study found that 75 percent of the participants who used an exercise app said they were more active. They also reported a drop in their BMI, or body mass index.

Depending on the product, you can track your heart rate, calories burned, distance you have run and the number of steps taken in a day. Some apps and devices help you with food choices and let you log your food intake. Dive deep into the technology, and you'll find devices that can offer feedback on the duration and quality of your sleep.

As to specifics, a fitness app is simply a program that you download onto your smartphone. You can use it to log information about your workouts and, depending on the app, receive data that tells you how well you're doing in achieving your goals. Some popular apps, such as MyFitnessPal, are free.

Fitness apps are highly personal. They help you stay aware of what you're eating, how much you're moving and whether you're improving. Your long-term goal is to exercise more. What an app can do is provide enough detail to set daily goals. It can make incremental progress interesting and even fun, which is both the heart and challenge of creating a new habit.

An activity tracker, like the popular Fitbit, is basically an exercise app that you wear. It uses sensors to detect your movement and, with an algorithm, translates the raw data into statistics about your progress. You then download the data onto your computer to use as you wish.

Whether you choose an app for your smartphone or the wearable tech of a fitness tracker, what you're getting is a helpful blend of coach, trainer and cheerleader.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I've been taking thyroid medication for several years, and my doctor says my blood tests are where they should be, but my face feels like sandpaper, my nails are brittle, and I'm losing so much hair that I can see my scalp. Could there be some underlying problem my physician is missing?

Dear Reader: Hair loss can be a distressing symptom, made all the more so when its cause is a mystery.

Your thyroid hormone levels are an obvious place to start, because both low and high thyroid levels can lead to hair and nail changes. Symptoms of high thyroid levels include hair loss, skin that is unusually smooth and warm, and nails that soften and loosen from the nail bed. The remaining hair becomes thinner, softer and does not hold a wave. Symptoms of low thyroid levels also include hair loss, including in the armpits and genital area, but the hair in this scenario is dull, coarse and fragile. As for the nails, they tend to be delicate, thin and have multiple grooves. That said, if your physician has done a complete panel of thyroid tests and the results have been normal, then most likely the function of your thyroid gland is not the cause of the brittle nails nor the hair loss.

That doesn't mean the thyroid isn't a factor. Autoimmune thyroid disease can lead to hair loss, both patchy and more diffuse, as well as inflammatory conditions of the skin. Such disease isn't always reflected in thyroid hormone levels. Checking anti-thyroid antibodies in the blood can identify autoimmune thyroid disease, and point you and your doctor in a clearer direction.

Hair loss also can be caused by androgenic alopecia, linked to an excess of androgens, a type of male hormone. These hormones are present in both men and women, but they're higher than normal in some women, such as those with congenital adrenal hyperplasia or polycystic ovarian disease, which is relatively common. Simply checking levels of testosterone and dehydroepiandrosterone (DHEA) can either rule out androgenic alopecia or suggest that it be explored further.

Another potential cause is medication. Some medications can lead to hair loss, so if your symptoms seem coincidental to starting a new medication, there might be an association.

Biotin deficiency, which is rare, can also cause hair loss and inflammation of the facial skin. But if you have a normal diet and eat eggs, you have a low likelihood of this condition. Nonetheless, it's something to rule out.

Iron deficiency also can lead to both brittle nails and hair loss. This doesn't explain the skin manifestations that you have, but if you are looking at other possibilities, checking the iron level of the blood should be part of the workup.

Any major illness can lead to hair loss and nail changes, and psychological stress can lead to hair loss. So, if there have been major stressors in your life, either physical or psychological, consider that a potential culprit.

In summary, if your thyroid levels are normal, it would be wise to check your thyroid antibodies, androgens and iron levels -- and your level of stress.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)