Entrepreneurs and investors in Silicon Valley love to talk about "pain points," the annoying parts of everyday experiences that represent opportunities for startups that can remove them. Uber eliminated the pain point of paying the cab driver at the end of your ride, Shyp fixed the pain point of returning unwanted items to a store, and so on.

But one pain point that gets surprisingly little attention is arguably the biggest one of all: actual pain, the chronic kind that affects more than 100 million Americans.

Inventor Shaun Rahimi thinks there's a reason you don't hear more about pain: The people who have it are ashamed to talk about it. "It's really depressing, really isolating," he says.

Rahimi speaks from experience. As a result of congenital defects in his spine, he has suffered nerve pain from his neck to his feet since he was in his teens. After college, where he studied biomedical engineering, his situation grew worse still when he developed carpal tunnel syndrome so severe he was forced to go on worker's comp.

After that ran out, Rahimi was in a dark place, unable to work, exercise or even sleep. His fate changed after a friend of his father's loaned him a machine called a TENS, short for transcutaneous electrical nerve stimulation. Widely used by doctors and physical therapists to control pain and stimulate healing by passing electrical current through affected areas, the devices cost thousands of dollars and can be tricky to use, but Rahimi experienced immediate, lasting relief the first time he used it. The relief was so complete, in fact, it caused him to wonder why people with pain aren't using TENS all the time.

The answer, he concluded, was the shame. Pain sufferers are embarrassed even to speak about it; walking around attached by wires to a bulky piece of medical equipment would be out of the question for most of them.

So Rahimi set out to make something they would be able to wear without shame or inconvenience. He teamed up with a product engineer, Kevin McCullough, and a top design firm, Huge, to create a discreet wireless patch that can be used to deliver TENS continuously and almost invisibly.

Not much bigger than a nicotine patch or a Band-Aid, Cur, as the product is called, is discreet enough to be worn under clothing, but in appearance it looks more like a fashionable wearable device than a medical aid. (That's no coincidence: Huge also helped design Nike's Fuelband and the Sonos speaker.) Rahimi hopes the appealing design will encourage users to wear the Cur where others can see it. "We're trying to create a conversation about pain that's never happened before," he says.

To make a TENS device that could be used without a skilled operator adjusting the settings, Rahimi and McCullough needed to design one that's capable of sensing where it's placed on the body and how the underlying muscles are responding to the current. Cur uses an accelerometer and bioimpedance sensors. The user can also provide direct feedback, which gets factored into the algorithm in much the same way a Nest thermostat "learns" how to optimize the temperature in a room over time.

Cur's crowdfunding campaign launches today. A device costs $149, although users will need to replace the adhesive pads every few weeks. The units are expected to ship in December.

Later this year, the company plans to validate Cur's effectiveness through trials at pain clinics. Until then, Rahimi has to be wary of making claims. But he's not shy about talking about his own experience with TENS. After two and a half years of a cramped existence defined largely by the pain in his back and arms -- he says he used to lie in bed for hours pressing a spot on his forearm, imagining he had a button there that could shut the pain off -- Rahimi is largely pain free. Back then, his only escape was strong painkillers with harsh side effects; now, his addiction is Crossfit.

"In 3 months I went from a situation where I was constantly in pain to where could control my pain, control my symptoms in a way that made me feel psychologically better," he says. "You can think again. You can be yourself again."