Where the pain is and where it radiates to, is an indication of where the bulging disk or arthritis (or both) is.  Because with some individual differences, there are basic 'zones' that each nerve covers.
Nerves leave your spinal column and branch out into the body - if you have lower back arthritis or bulging disks, it is the nerves that go out into your legs that get compressed.  It's that spot where the nerve leaves the spine, where a disk or arthritis can press on it.
In the lower back, nerves that go down the side of the leg or the back of the leg ('sciatica') can be compressed.
Many people are helped by physical therapy.  This lessens muscle spasms and makes more room for things that are getting compressed.  The more active you are, the more exercise and stretching you need.  And to keep them working, you have to do them every day.  EVERY DAY.  Many people don't have the discipline at first, but quite a few people learn that stretching and exercises can even eliminate the need for medications or surgery.
Especially effective are stretches that stretch the back of the leg.  Such as reaching the knee forward to the chest.  And remember, there is a good way to stretch and a bad one.  Very forceful stretching, or bouncing, does the exact opposite of what effective stretching does - that type of stuff actually tightens the muscles up, doesn't loosen them!!!!
There's a great softbound book called just 'STRETCHING' that has simple line drawings in it, and a selection of stretches for each type of activity you do.
It is really unbelievable to most people that exercises could do so much good, so they often don't stick with it.
In many cases, heat makes things swell up more, and compresses nerves more.  People love to put on heat because it makes the muscles loosen up and feel so good, ,but it also can inflame tissues that are getting pressure on them.
Sometimes the trick is to apply heat briefly before you start to be active, to loosen up muscles, and then apply ice after activity, to lessen swelling.  Sometimes a muscle relaxant can assist.  Ask a doctor.
Another amazingly simple yet effective treatment is traction.  This also loosens muscles and makes more room.
Another very, very effective approach is losing weight.  Weight on the front of the body - belly, chest, can pull on the lower back.  Another effective treatment is to adjust how one sits.  Keeping the knees higher than the hips loosens muscles and stretches the lower back.
When nerves are compressed, many people's bodies are 'wired' so that, the way their nerves work, is if they have a little change in the bones and disks, their muscles react by clamping down hard, big time, and that muscle spasm can spread from one muscle to the other!  Often it's the people whose back muscles are most shortened and tight, that have the most problem!!!  Certain activities, the way one sits, drives a car, can tighten and shorten those muscles.
That muscle contraction is what produces most of the pain and really clamps down on the nerves!!!!  It's the body's reaction for survival, 'splinting' an injured part, and some people's bodies do it more than others.  It can then be shocking to see how much stretching and exercising will actually do to reduce or even stop pain.
Another real surprise is that resting 'until the pain goes away' isn't always the best solution.  Finding a comfortable position and not moving is very, very tempting.  And it's quite often the worst choice possible!!!   Often getting moving, even if it requires muscle relaxants and pain meds, works out better in the long run!!!  As quickly as one can get moving, stretching and working those muscles, that's often the better. 
I am not one of the people who likes chiropractors.  I think adjustments avoid the basic problem and keep the person dependent on paying the chiropractor.  I also think adjustments can damage further some back problems.  So can traction, so I think it's very, very important to have a very good quality xray or even MRI, to make darn sure you know exactly what is going on in that spine, before deciding on a treatment, or who's going to do it.  
Disks and arthritis are nothing to fool with or treat casually.  It's EXTREMELY important to get a very, very good picture of what's happening.  It's exactly like equine lameness - the 'right treatment' depends completely on what's going on in that leg, NOT on what you see on the surface, as 'symptoms'.  
So as you can see people are often not doing the best thing for their lower back pain.  Almost always a person can make changes that will control that pain.   The trick is actually to AVOID surgery.  It isn't a 'solution' as much as a last ditch effort to relieve pain.  If you want to stay active and manage pain, rather than ONLY manage pain, you do everything first, and you go into surgery 'fighting fit', stretched, active, in shape, weight down, and loose and supple.  Think of surgery not as a 'miracle cure' but as a part of your attack on lower back pain...MAYBE.
If it gets to the point where surgery is needed - LET THE BUYER BEWARE!!!!!  There are so many 'instant laser spine clinics' and these are not always a cost effective or even safe approach.  Be very, very careful who you consider having cut on your back.  A good surgeon can do amazing things for you and a hack can leave you in far worse shape.
Don't be fooled by terms such as 'minimally invasive' or 'microsurgery'.  Very few surgeons really are doing the latest least invasive, micro methods.  The trick with back surgery is to do as little as possible and as much as necessary, WHERE it is necessary.  Older surgeries involved removing a lot of bone - the more these have been refined over the years the less they are removing!!! The best tested, most innovative surgeries involve doing not hardly anything!  Just a little clean up around the nerve and very, very little tissue, especially bone, actually being disturbed or removed.  Check out Pittsburgh Allegheny Regional for an example.  
Some people DO need the surgery known as 'fusion'.  It involves removing a disk that has really been destroyed and fusing the two bones on each side of where the disk was.  Sometimes there is no other real solution.  The disk is extremely bulging out and there is no less surgery that's going to work.  Fusion has been refined and when it is needed, that's what is needed.
There are new amazing methods being developed,  even, replacing disks with artificial steel or high density plastic 'appliances'.  These are being done in Germany and some other countries, but most American doctors are still very leery.  There are very few really good reviewed, juried studies on the results.   Most smart surgeons like to wait until a lot of research has been done.  The one unsolvable problem so far with artificial disks is, say someone got one, and then got in a car accident and injured their spine AGAIN.   This isn't rare, and when it comes to that, the artificial disks are a flat out pie eyed mess to re-do ('revise').  
Many of the 'instant' clinics, what they do is while they are in there, they inject cortisone into the nerves.  A person feels great when they wake up, but in a couple months they are pretty much back where they were.  Then they want another surgery.  Which is the whole point.
The other thing to keep in mind is that your back, well, your body as a whole, is not a collection of points that cause specific symptoms.  It's a system, that works all together.  Fitness, activity, suppleness through stretching, lifting and moving and sitting correctly, and at times, yes, even surgery, are all a part of a healthy, reduced pain existence.