Russian President Vladimir Putin attends a news conference after a meeting with Italian Prime Minister Matteo Renzi in the Kremlin on March 5. (AP Photo/Sergei Karpukhin, Pool)

Everyone has their off days, but when you're the proudly virile and uncontested leader of one of the most-watched countries in the world, your days off make people nervous. Russian President Vladimir Putin hasn't been seen for days, and now people are beginning to wonder why.

On Thursday, Putin's spokesman announced that the president would not attend a meeting with the Federal Security Service (FSB), which he usually attends. But no, Putin was "absolutely" healthy, Dmitry Peskov told Russia's Ekho Moskvy, before adding that the president's handshake was so strong it could  “break your hand.”

Putin's absence at the FSB meeting comes just a day after he unexpectedly canceled a trip to Kazakhstan. "The visit has been canceled. It looks like he [Putin] has fallen ill," an anonymous Kazakh official told Reuters afterward, prompting a flurry of  speculation.

To make matters more confusing, on Wednesday the Kremlin released an image of Putin meeting with the regional governor of Karelia. But local Web site Vesti Karelii reported that Putin actually had met with the head of the Republic of Karelia, Alexander Khudilainen, on March 4. In fact, RBC.ru reported that a number of events posted by the Kremlin appeared to have been recycled from earlier events. If this is correct, the last time Putin was seen in public may have been March 5, when he met the Italian prime minister in Moscow.

On Friday, as speculation grew further, state TV released footage showing Putin meeting with the head of Russia's Supreme Court at his residence outside of Moscow. It was not clear, however, when the meeting had occurred.

Getting worked up by an absence of a few days may seem silly, but these things happen in authoritarian regimes: North Korea's Kim Jong Un disappeared for weeks last year, intriguing the world. In that case, Kim later reappeared with no real explanation and continued going about his business as usual (don't be surprised if that happens in Russia, too). Russia isn't North Korea, but it's still an intensely personalized political system. Little of political substance happens without Putin's personal approval, and it's hard to imagine how the country would respond if he really were sick.

There's also a history here. At the end of the Soviet era, three separate Communist Party chiefs died suddenly in office, and during the end of Boris Yeltsin's time as president of Russia, alcoholism and poor health led to a number of unexplained and embarrassing absences. Again, Putin is certainly no Yeltsin -- he's a black-belt in judo and known to be extremely health conscious -- but many Russians now assume that the state would lie about the health of its leaders.

This isn't the first time there has been speculation about Putin's health. In 2012, there were a series of rumors when he was briefly absent from public life; most focused on some kind of back ailment. Putin returned, with little explanation. Then, last year, after a New York Post article said Putin might have cancer, Peskov told reporters: “Bite your tongue! Everything’s fine."

Now, with the Russian president absent again, Putin's health is the talk of Moscow. But while rumors are everywhere (some say he has had a stroke; others suggest plastic surgery) it's all just speculation at the moment. On Twitter, users have posted their own theories under the hashtag #ПутинУмер or #PutinIsDead. Another, less macabre, hashtag -- #WhereIsPutin -- is also popular.

Related:

Italian prime minister in Moscow to discuss Russia-E.U. ties

BBC: Nemtsov’s daughter says Putin to blame for death

Russia has a history of finding convenient Muslim scapegoats

This post has been updated to include mention of the images released of Putin on Friday.