Investing in the health care sector isn't easy. Where do you start out? From medical device companies to big pharma to small biotech firms bristling with boom-or-bust prospects, it's tough for investors new to this sector to understand the intricacies unique to health care. Fortunately, there's an easy place to look for blue-chip, tried-and-true stocks: the Dow Jones Industrial Average (^DJI -0.11%).

Four big-time health care stocks call the Dow home, but which one is the best pick for your money? In this five-part series, we'll take an in-depth look into why each health care stock on the Dow is worth investing in -- and in the final installment, we'll select a winner. Let's start out by checking in with maybe the most well-known company of them all: Johnson & Johnson (JNJ -0.69%).

Looking at the numbers
It's tough to argue with Johnson & Johnson's recent track record. This stock's picked up more than 14% over the past six months, and almost 8.3% just since the start of 2013. Those are gains any investor could be happy with, particularly with such a giant and far-reaching blue chipper like this: J&J has a presence in seemingly every corner of the health care industry, from pharmaceuticals to medical devices to consumer care products and more.

All that diversity helps J&J stave off the big up-and-down swings and makes it a rewarding, stable company for income investors. The stock boasts a 3.2% dividend yield -- good enough for tenth overall on the Dow and easily beating the index's average yield of 2.86%. Johnson & Johnson's payout ratio of 62% is on the pricey side, but this company's breadth and solid cash flow mean that it can withstand such pressures better than most stocks. Don't expect J&J to keep dividend investors up at night.

On a pure financial basis, it's hard to argue with J&J. But that's all in the present -- where's this company headed in the future?

Risks and opportunities from medical devices
Fortunately, Johnson & Johnson's made a number of key moves -- and developed a promising pipeline of drugs -- that will fuel the company's growth for years to come. However, risks loom for J&J, hurdles that could derail the company's future that investors need to keep an eye on.

Let's start out in the medical device industry. J&J's nearly $20 billion purchase of Synthes last year opened up a massive opportunity in the orthopedics market. Expect this market to grow significantly in the years to come as populations in advanced economies age and obesity rates continue to remain high. J&J's well-positioned to capitalize on such trends, with the Synthes acquisition helping fuel the company's orthopedics division to growth of more than 34% last year.

In all, the branch alone recorded sales of $7.8 billion in 2012 -- less than 12% behind than the entire revenue of major orthopedics company Stryker (SYK 0.58%), one of the medical device industry's larger names, which pulled in $8.7 billion in full-year 2012 sales. With orthopedics making up more than 11% of J&J's revenue, obesity and aging trends should make investors confident in this division's prospects.

Medical devices make up the largest single segment of J&J's business, but outside of orthopedics, the rest of the branch saw sluggish growth last year. Orthopedics won't always grow as spectacularly as it did in 2012, and if J&J can't turn around some of its other medical device businesses -- in particular, its cardiovascular division, which lost more  than 13% in 2012 -- the company could be facing a slowdown in its largest business unit.

J&J's recent spate of hip implant recalls could even hurt the orthopedics segment going forward, with rivals like the aforementioned Stryker looking to poach market share as Johnson & Johnson battles lawsuits and PR damage. That's not conducive to the growth investors want to see, particularly when picking the top health care stock in the Dow.

Fortunately, J&J's more than just medical devices. Pharmaceuticals -- the high-risk, high-reward market movers of the health care sector -- make up a substantial share of this company.

Pharmaceuticals: The other side of growth
Prostate cancer drug Zytiga continues to top expectations, recording more than 300% sales growth last year to record revenue of $961 million. Analysts have pegged peak sales of the drug at $1.8 billion by 2015, so it's still got plenty of room to grow. Although investors should be wary of competition -- Medivation's (MDVN) rival prostate cancer drug Xtandi could hit peak sales of $2.2 billion by 2021, according to analyst projections -- Zytiga still represents blockbuster sales for Johnson & Johnson's near future, even if it's eventually lapped by the likes of Xtandi. There's no shame in $1.8 billion.

It's hardly the only drug that investors should watch. While Johnson & Johnson's taken a hit from generic competition for the likes of neuroscience products Concerta and Risperdal among others -- both top sellers for the company -- J&J's still surging behind top-selling autoimminue therapy Remicade. Merck (MRK 0.10%) relinquished the rights to Remicade in numerous markets abroad -- a good thing for J&J, which conducts the majority of its pharmaceutical sales outside the U.S. Merck and J&J now split the profits of Remicade equally in markets where Merck still has rights, where in the past Merck pulled in 58% of the profit in such markets. Remicade made more than $6 billion for J&J in 2012 with growth of more than 15%; investors can count on this cash cow to keep on producing in the near future.

With a bountiful pipeline, including promising rheumatoid arthritis drug sirukumab, J&J's pharmaceutical branch looks well-set to withstand patent expirations in the future. Look for pharmaceuticals to power much of this company's growth alongside its orthopedics division.

As stable as they come
The key word for Johnson & Johnson is stability. This stock hasn't quite grown like some of its peers recently -- even with year-to-date growth that investors will happily accept -- but its breadth and reach across the entire health care industry makes it a pick that won't disappoint cautious shareholders. J&J's a great pick for income investors or newcomers to the health care industry, particularly those who don't want to deal with the stress of high-profile FDA drug approvals that can make or break pure pharmaceutical companies. Is it the best health care stock in the Dow, however? Keep following the series throughout the week to find out.