Nurse!

Tyrese has offered an explanation for his erratic behavior in recent weeks -- he says a new medication is to blame.

Tyrese claims his online meltdown a couple weeks ago was caused by the drug Rexulti, used to treat depression, having an adverse effect on him ... but he's off it now and getting back to normal.

The actor says the meds made him do things over the past 2 months that effected a lot of people and he wants them to know he's sorry.

As we've reported ... Tyrese is in a bitter court battle with his ex, Norma Gibson, and he says doctors recommended the meds to him to handle the stress.

Zahn McClarnon, who has a reoccurring role on the second season of "Westworld," sustained a very bad head injury earlier this week that landed him in ICU and caused production to stop ... sources tell TMZ.

Sources familiar with the situation tell us, Zahn fell at his home and hit his head. We're told the impact caused serious trauma and he was rushed to the ICU.

Our sources say Zahn is still in the hospital but is "on the mend."

TMZ broke the story -- production on the HBO hit was stalled after a cast member suffered a medical emergency off set -- but the actor's identity remained a mystery.

Zahn is known for his performance as Hanzee Dent on "Fargo," and his long running stint on "Longmire."

As for production on "Westworld," as of the time this story posted, it's still suspended.

Deshaun Watson has broken his silence on his devastating season-ending knee injury -- saying he knows it's all part of God's plan.

The Houston Texans rookie QB phenom tore his ACL during Thursday's team practice -- which SUUUUUCKKKKS for football fans ... especially in Houston.

"They say you never miss it until it's gone and even though it's not gone for long, I already miss it," Watson wrote.

"Yesterday I felt like I let my teammates, my fans and my family down. However, as a child of God, I understand that everything happens for a reason. He DON’T make mistakes!"

Watson thanked all his fans, teammates and other pro athletes who reached out and offered support -- saying, "I am humbled and can only say thank you from the depths of my heart."

"I promise that I will continue to work diligently so that this team can one day bring a championship to Houston, and when I return, I will be better, stronger and more focused than ever before! Now the grind begins."

El Chapo can't remember a damn thing and is depressed as hell ... and that's why his lawyers are begging a judge to let a doc take a look at him in jail.

Lawyers for the drug lord want the judge to allow for a neuropsychological evaluation at the Metropolitan Correctional Facility because in just the last month he can't remember people, places and events.

In new legal docs obtained by TMZ ... lawyers say Chapo suffers from headaches, ringing in his ears and throat pain ... claiming none of it has been looked at by doctors. Plus ... Chapo's been denied from buying simple things like bottled water, batteries for his radio and personal hygiene items.

Chapo's condition, lawyers claim, is a result of complete isolation, frigid cell temps, lack of clean bed covers and no fresh air, among other things. Lawyers also claim shortly after just one visit from his sister, the government revoked her visa and she can no longer enter the U.S.

We broke the story ... Chapo's lawyers tried getting him moved to general population but a judge basically told him to stop bitching.

Filming for season 2 of "Westworld" has been suspended after a cast member suffered a medical emergency ... TMZ has learned.

A rep for HBO tells us that filming at one of the show's two units has been temporarily halted after a cast member with a recurring role had a recent emergency off set.

One source close to the production tells the injury was sustained by a male member of the cast who fell and hit his head at home ... we're told it's serious.

2:58 PM PT -- Prince's rep has now confirmed to TMZ that Prince was involved in a traffic accident and was struck by another vehicle while driving to his college campus. His rep adds, "he is now resting at home and thanks everyone for their well wishes."

Michael Jackson's oldest son, Prince, was taken to the hospital by ambulance Thursday morning after laying his chopper down on a slick Los Angeles street ... TMZ has learned.

Sources connected to the 20-year-old tell us, Prince was riding in light rain when he lost control of his bike. He was banged up enough that an ambulance was called and he was taken to a nearby ER.

MJ's son was lucky ... no broken bones, so after doctors checked him out he was released.

Prince was good to go and actually went right to Loyola Marymount University and made it in time for class.

Wendy Williams fainted in the middle of her show Tuesday morning ... and it happened live on the air.

Wendy was dressed up as the Statue of Liberty for her show, but her Halloween costume got the best of her about 48 minutes into the show. Right in the middle of a sentence ... she stuttered, then got wobbly on her feet before collapsing to the ground.

Wendy's show airs live on the East coast ... so when she passed out, producers quickly cut to black and then a commercial.

When they returned Wendy explained she overheated from her costume. We've learned the fire department responded to the studio. Unclear what her condition is, but she was alright enough to finish the show.

"Dancing with the Stars" front-runner Lindsey Stirling is in excruciating pain after suffering a devastating injury that could knock her off the show.

'DWTS' sources tell TMZ ... Lindsey was badly hurt Sunday in rehearsal practicing a rapid dance move and was rushed to a hospital. We've learned she suffered a blunt rib injury and possible separation, and the pain's so immense it could force her to bow out of Monday's show.

Lindsey's dance partner, Mark Ballas, went to the hospital with Lindsey, and she asked him what would happen if she's unable to perform Monday. It's crushing ... he tells Lindsey she'll have to forfeit.

A Sephora cosmetics store in Hollywood cared more about peddling lipstick than the oral health of customers, and now a woman is stuck with a lifelong disease ... according to a new suit.

A California woman claims she visited the store in October 2015 and sampled a lipstick from one of the "common use" tubes on display ... and ended up with herpes on her lip. She says the infection was diagnosed by medical pros and she claims she never had herpes or cold sores before this Sephora visit.

According to the docs ... Sephora failed to clearly warn the woman and other customers of the risk of getting herpes or other diseases from trying on the lipstick samples. She says if she would have known ... she would've avoided them like the plague.

The woman claims other lipstick companies have proven methods of avoiding herpes exposure -- like individual samples or assistance from trained professionals -- but Sephora cared too much about making a quick buck to bother.

She's suing the cosmetics chain for the emotional distress over an "incurable lifelong affliction" she says she now has to deal with as a result of using its lipstick samples.

If Simon Cowell's being honest ... he's going to recover just fine from that nasty fall down a flight of stairs.

Simon was driven back to his London home Friday after spending a few hours in the hospital. He gave the thumbs-up on his way into the house. As we reported, he had to get a CAT scan after fainting while walking up a steep staircase.

7:50 AM PT -- Simon actually fell backwards down the stairs. We're told he had already gone to the kitchen, and was on his way back upstairs when he fainted and tumbled.

Simon Cowell was rushed to a hospital early Friday morning after falling down a flight of stairs.

We're told Simon was asleep in the upstairs bedroom of his London home. He woke up in the middle of the night, felt dizzy as he tried to go downstairs to the kitchen for some milk. We're told he fainted and tumbled to the bottom of the staircase.

An ambulance came, put him in a neck brace and neighbors saw Cowell placed in the back of the ambulance on a stretcher.

We're told doctors have performed a CAT scan and more tests are being performed.

He's in stable condition and still in the hospital.

Simon's girlfriend/baby mama Lauren Silverman was in New York visiting her son and is currently on a plane flying back to London to be with Simon.

Tom Hanks and Mary-Louise Parker sprang into action when a moderator's nose started bleeding onstage -- Tom distracted the crowd while Mary-Louise played the more pragmatic role.

The hilarious/awkward incident went down Wednesday night at The Plaza Hotel in NYC at a benefit dinner for the David Lynch Foundation. It happened fast -- it was just 3 minutes into the chat when the head of the foundation, Bob Roth, started gushing blood.

Tom and Mary-Louise -- there to talk about transcendental meditation and how it can help veterans suffering from PTSD -- did what they could: Tom took the stand-up comic route while Mary played the role of nurse.

Joe Theismann says watching Gordon Hayward's leg snap during NBA's opening night took him right back to 1985 ... an eerie reminder of that fateful encounter with Lawrence Taylor.

Of course, LT snapped Theismann's leg live on "Monday Night Football" -- essentially ending Joe's career. It remains one of the most gruesome injuries of all time.

Theismann tells TMZ Sports he really does understand Hayward's pain -- and feels terrible every time he watches a similar injury on TV.

The good news ... Theismann says he's optimistic Hayward can recover and go on to have a strong career in the NBA -- as long as he follows two important rules.

Jesus Campos, the Mandalay Bay security guard who alerted police to the Las Vegas shooter, is speaking out for the first time about the violent encounter that left him with gunshot wounds.

Jesus opened up to Ellen DeGeneres ... detailing the harrowing moments leading up to him discovering Stephen Paddock on the 32nd floor, just as he was starting to open fire on the crowd of concertgoers below.

He thinks a loud slamming door during his routine check of the floor is what tipped off his location to Paddock, who then started shooting into the hallway -- and hit Campos in the leg.

Elvis Presley Enterprises runs a disease-infested hotel where the water is full of bacteria infiltrating guests' lungs ... according to a new lawsuit.

The company that runs all things Elvis has just been sued by Jennifer Walker, who says she stayed at the Guest House at Graceland this summer -- and contracted Legionnaires' disease during the vacay.

Walker says she spent a lot of time at the hotel pool and hot tub and started suffering symptoms of the chronic lung affliction -- such as coughing, difficulty breathing and loss of appetite -- and was diagnosed with Legionnaires' later that same month.

According to the suit, a county health department investigation of the hotel -- which is right next to Graceland -- found the sprinkler system tested positive for Legionnella bacteria.

There have been other deaths allegedly tied to an outbreak at the hotel, and EPE is already facing a wrongful death lawsuit.

Walker is suing for negligence and wants an unspecified amount in damages. To be clear, she is not suing Elvis' estate or the actual Graceland property.

Gerard Butler was hospitalized after he says he got run off the road and took a bad spill on his bike.

Sources close to Butler tell TMZ ... he was riding his motorcycle in L.A. when he got cut off by a car, causing him to crash. Someone called 911, paramedics came and took Gerard to a nearby hospital where he was treated for his injuries. Lucky for him ... no broken bones ... just cuts and bruises.

Lucky for Gerard he's not laid up. His climate change disaster flick, "Geostorm," comes out next week, and he's able to promote it like usual, despite being a little banged up.