The stock market has been under a lot of pressure this year due to concerns about rising inflation and an economic downturn. While stock market sell-offs can be challenging, they often provide investors with great buying opportunities.

One benefit of lower stock prices is that dividend yields move in the opposite direction, meaning dividend investors can lock in some much higher yields these days. Three dividend stocks that look like great opportunities right now are Medical Properties Trust (MPW 2.65%)Kinder Morgan (KMI -0.32%), and Verizon (VZ 2.85%). Here's why investors who already own shares might want to consider doubling up on their positions.

Continuing to grow at a healthy rate

Shares of Medical Properties Trust have tumbled more than 30% this year. That sell-off has pushed the real estate investment trust's (REIT) dividend yield up over 7%. 

That sell-off doesn't make much sense. The hospital-focused healthcare REIT recently reported solid second-quarter results. Its normalized funds from operations (FFO) per share grew by 7%, driven by acquisitions completed over the past year. 

Meanwhile, the REIT continued to take steps to grow its portfolio. The company acquired two U.S. hospitals in April for $80 million. It also bought three facilities in Spain and agreed to develop three more in that country. The company also agreed to develop a behavioral healthcare facility in the U.S. and acquire a hospital in Colombia. These new additions to Medical Properties' portfolio should enable the REIT to continue growing its FFO and increasing its dividend, something it has done for the last nine straight years. 

Plenty of fuel to keep growing the dividend

Kinder Morgan's stock price has fallen about 8% from its recent high despite strong oil and gas market conditions. That decline has pushed the pipeline stock's dividend yield up over 6%.

Shares of Kinder Morgan have fallen even though the pipeline giant is having a great year. The company recently reported stronger-than-expected second-quarter results. Because of its strong performance and current market conditions, it raised its full-year guidance by 5%. 

Meanwhile, higher energy prices are enabling Kinder Morgan to move forward with additional expansion projects. The company recently approved several natural gas pipeline expansion projects to support growing demand. Meanwhile, it also made another deal to expand its renewable natural gas operations. These investments should enable the company to continue growing its cash flow, giving it the fuel to keep increasing its high-yielding dividend, which it has done for the last five straight years. 

Battling some short-term headwinds

Shares of Verizon have slumped nearly 20% from their peak this year. That's driven the telecom giant's dividend yield up to 5.7%.

One issue weighing on Verizon's stock has been its lackluster financial performance. The company's earnings dipped in the second quarter due to the sale of Verizon Media, higher device subsidies and promotional spending, and inflationary cost pressures.

However, the company continues to generate lots of cash, producing $17.7 billion in cash from operating activities in the first half of 2022. That was enough to cover its capital expenditures ($10.5 billion) and dividend outlay ($5.4 billion) with room to spare. Because Verizon generated excess cash and sold its media business, debt fell by $5 billion, improving its leverage ratio to 2.7. 

Meanwhile, Verizon is taking action to improve its profitable growth opportunities in the near and long term, and it expects its financial performance to improve in the second half. These factors all suggest that Verizon's lucrative dividend is on a firm foundation. With debt coming down and profitability on track to improve, Verizon should be able to continue increasing its dividend, which it has done for 15 straight years. 

These great dividend stocks are on sale

With their share prices slumping this year, Medical Properties Trust, Kinder Morgan, and Verizon all offer even higher dividend yields. Meanwhile, these companies should be able to continue growing their big-time payouts in the future. Now looks like a great time to double up on these dividend stocks.