Heartburn (and/or GERD) is miserable and a huge block of the population suffers from it including those who try to live a healthy lifestyle. It can be distracting and even incapacitating for many, many guys.
Most of us never stop to think what might be behind the issue and immediately reach for a pill to help. This can be a dangerous appoach as lowered stomach acid levels are associated with an increased risk of dementia.  This may be because stomach acid, interestingly enough, wards off infections, especially in the lungs. And we know that long term infections lead to inflammation and dementia is very sensitive to inflammation. (See the PPI item below for even more reasons.)
Instead of immediately popping a pill, I recommend examining the mountain of material that researchers have uncovered, mostly in the last decade, as to what can cause and resolve these issues. Of course, work with your doctor if you have GERD (reflux) and/or heartburn as they can be a sign of ulcers, hiatal hernias, gall bladder issues and other so on.
1. Nexium, Prilosec and PPI's: Nexium is the very latest PPI (Proton Pump Inhibitor) and it is very expensive, especially when compared to Prilosec which is over-the-counter. Considerable caution should be exercised in taking PPI's long term: they have been linked to fractures, pneumonia, Clostridium difficile and stomach (gastric) nodules/polyps and possibly atrophic gastritis.  Discuss with your doctor.
2. Antacids. Many people pop these like candy, but extreme caution is in order here as well. Many antacids have aluminum in them. Manufacturers claim that the aluminum in their antacid products is largely non-bioavailable. However, I urge extreme caution here as aluminum is a definite neuron destroyer and has been linked with Alzheimer-like symptoms at even low consumption levels. See my link on Aluminum and the Brain for more details.
3. NSAIDs (Advil, Aleve, Ibuprofen, Aspirin, etc.). All of these are notoriously hard on the GI tract. Long term users of NSAIDs almost invariably have GI problems of one sort of another that can lead to stomach upset, heartburn and even ulcers.
4. Dark Chocolate and Cacao. I can't say enough good things about these two nutritional giants. (See my links on Dark Chocolate and the Kuna.) Unfortunately, in sensitive people (like me), they relax the valve between the stomach and throat and allow stomach acids to enter the espophagus. I actually suffer with this issue and solve it by eating only one square of dark chocolate. This does not distress me, because the latest research shows that it only takes a small amount of dark chocolate - about one square - to dramatically reduce inflammation levels.
5. H. Pylori. Almost all of us are infected with this gut bacteria but for some of us it goes out of control and leads potentially to heartburn, ulcers and stomach cancer. Broccoli sprouts help keep these critters at bay  as does cranberry juice. 
6. Stress. Webmd reports what we all know instinctively: job stress aggravates and may cause GERD in some cases.  Of course, it's not just job-related stress that can cause GI problems, but any perceived stress . (See my link on Stress Management for practical solutions.)
7. Lifestyle "Sins". Gorging, being overweight and smoking are all risk factors for heartburn and GERD.
8. Foods. Many people are sensitive to certain foods. Many guys find that fatty or greasy foods trigger this problem, yet another reason to consider a Low Fat Diet. Diary bothers still others as can acidic foods such as tomatoes.
9. Ginger. Ginger has several studies showing its anti-nausea powers. 
10. Vinegar. This is counterintutive but powerful solution for many, as it provides an immediate, albeit suprising, relief from heartburn.
11. Chamomile and Peppermint. I could not find the studies for these two natural "antacids", but they have a long-standing reputation for providing heartburn relief. A little goes a long ways in the case of these two powerhouses.
12) Saltines and/or Club Soda. These two are mild antacids, but without the aluminum! These do a nice of neutralizing mild to moderate stomach acid on a short term basis.
13) Sleeping Position. Sleeping on your right side will actually lead to more stomach acid in your esophagus than sleeping on your back or left side. 
14. Tea Extracts. Various tea extracts were found to inhibit H. Pylori, which can cause all manner of stomach disorders, without affecting good interestinal bacteria.  The authors found, in general, that extraction time had to be of sufficient time however.
1) The Amer J of Gastroenterology, 1 Sept 2003, 98:S57, "Oral broccoli sprouts eradicate Helicobacter pylori infection"
2) J of Gastroenterology and Hepatology, 23(2):S175-S180, Special Issue: Proceedings of the 12th Taishotoyama International Symposium on Gastroenterology, April 27-April 28, 2007, Shimoda, Japan, published Online: 1 Dec 2008, "Growth inhibitory action of cranberry on Helicobacter pylori"
4) Obstetrics and Gynecology, 2004, 103(4):639-45, "A randomized controlled trial of ginger to treat nausea and vomiting in pregnancy."
5) J of the Amer Geriatrics Society, Aug 2007, 55:1253, "The Association Between Cognition and Histamine-2 Receptor Antagonists in African Americans"
6) JAMA, Oct 27 2004, 292(16), "Risk of Community-Acquired Pneumonia and Use of Gastric Acid Suppressive Drugs"
7) Alimentary Pharmacology & Therapeutics, Aug 2005, 22:55-63, "Review article: the long-term use of proton-pump inhibitors"
8) http://newoldage.blogs.nytimes.com/2010/08/11/ a-caution-on-antacids-for-older-patients/?ref=health, "A Caution on Acid-Reducers for Older Patients"
9) Journal of Nervous & Mental Disease, Mar 2010, 198(3):226-229, "Psychological Stress and Self-Reported Functional Gastrointestinal Disorders"
10) Shape, Nov 2009, p. 73.
11) J Med Food, 2011 Jun 11, "Inhibitory Potential of Tea Polyphenolics and Influence of Extraction Time Against Helicobacter pylori and Lack of Inhibition of Beneficial Lactic Acid Bacteria"